Homework Help: Math: Statistics

Recent Homework Questions About Statistics

statistics
. A new diet is claimed to increase the speed of weight loss. A study with a large number of volunteers showed a mean weight loss of 3.5 pounds in a week. A random sample of 8 volunteers followed the diet and recorded their weight loss at the end of the week. The results ...
Saturday, November 10, 2012 at 11:01pm

statistics
An independent-measures study with n = 6 in each sample, produces a sample mean difference of 4 points and a pooled variance of 12. What is the value for the t statistic? a. 1 b. 2 c. 4/√2 d. 4/√8
Saturday, November 10, 2012 at 7:05pm

Statistics
Use the multiple regression equation to predict a person's salary. Assume that the variable A is the number of years of college. Assume that the variable B is the number of years of experience. Suppose the person has 7 years of college and 3 years of experience. What ...
Friday, November 9, 2012 at 11:09pm

statistics
A normal distribution has a mean of 36 and standard deviation of 4. What proportion of the distribution consisted of scores between x=34 and x=38? a, 0.6915 b, 2(0.3085)=0.6170 c, 0.1915 d, 2(0.1915)=0.3930
Friday, November 9, 2012 at 7:35pm

statistics
A researcher administered a treatment to a sample of participants selected from a population of 80. If the researcher obtains a sample mean of M=88. Which combination of factors is most likely to result in rejecting the null hypothesis? a, alpha level=0.01 and standard ...
Friday, November 9, 2012 at 7:35pm

statistics
1. A bag of colored blocks contains the following assortment of colors: red (13), blue (12), orange (21), purple (14), green (14), and yellow (6). Construct the probability distribution for x.
Friday, November 9, 2012 at 7:06pm

statistics
Which of the following situations can be best modeled using a continuous distribution? a) Number of heads in 10 flips of coin. b) Number of customers/hr. c) Time between arrivals of two customers. d) Yes or no answer. e) Number of product defects/hr.
Friday, November 9, 2012 at 10:43am

Statistics
male heights are normaly distributed with a mean of 70 and a standard deviation of 2.8 inches. for two randomly selected guys, what's the probability that both of them are 67 inches or shorter? show calculations. Can someone please help me quickly with this question?
Thursday, November 8, 2012 at 4:54pm

Statistics
Suppose the correlation between two variables is -0.57. If each of the y-values is multiplied by -1, which of the following is true about the new scatterplot? It slopes up to the right, and the correlation is -0.57 It slopes up to the right, and the correlation is +0.57 It ...
Thursday, November 8, 2012 at 9:35am

Statistics
New York and Pennsylvania have progressive toll roads. Upon entering the toll road the driver receives a ticket marking the location and time of entrance. Upon exiting the mileage is computed and the driver pays the toll. Which of the following would you expect to be true ...
Thursday, November 8, 2012 at 9:35am

Statistics
The value of the correlation coefficient can be between 0 and 1.True or false?
Wednesday, November 7, 2012 at 9:20pm

statistics
Of the 15 teams in the National Hockey League Eastern Conference, three of them are based in canadian cities. Each year, eight of these teams qualify for the playoffs. Assuming that all the 15 teams have an equal chance of getting into the playoffs, what is the probability ...
Wednesday, November 7, 2012 at 8:57pm

statistics
A normal distribution has a mean of 100 and standard deviation of 20. What is the probability of randomly selecting a score less than 130 from this distribution? a, p=0.9032 b, p=0.9332 c, p=0.0968 d, p=0.0668
Wednesday, November 7, 2012 at 8:48pm

statistics
Under what circumstances can a very small treatment effect still be significant? a, if the sample size (n) is very large b, if the sample standard deviation is very large c, if the standard error of M is very large d, all of the other factors are likely to produce a ...
Wednesday, November 7, 2012 at 8:46pm

statistics
90% confidence; the sample size is 1150 of which 40% are successes.
Wednesday, November 7, 2012 at 6:27pm

Statistics
A random sample of 14 evenings at the O'Sullivan house hold showed that the family received an average of 2.4 solicitation calls each evening. The sample standard deviation was s= 0.9. Find a 99% confidence interval for the population mean number of solicitation calls this...
Wednesday, November 7, 2012 at 5:57pm

statistics
An automatic machine that fills bags of unpopped popcorn is operating properly if the weights are independently and normally distributed with a mean of 114 grams and a standard deviation of 4.9 grams. Find the probability that if 7 bags are randomly selected, their mean weight...
Wednesday, November 7, 2012 at 4:00pm

Statistics
Let’s suppose a randomly selected sample of 75 American teenagers watches an average of 1472 hours of television per year with a standard deviation of 250 hours. Construct the 95% confidence interval (CI) for the mean number of hours American teenagers watch television ...
Wednesday, November 7, 2012 at 11:39am

Statistics
Body masses were measured for five female and five male adult Anolis lizards. Test the hypothesis of no difference in mean body mass of females and males versus the alternative that a difference exists. Use a 5% level of significance. Body Mass (g): Females 55,49,60,51,56 and ...
Wednesday, November 7, 2012 at 3:23am

Statistics
Lead (Pb) concentrations were measured in waterfowl eggshell samples from two locations. In n1 = 41 samples from a location downstream from a paper mill, the mean Pb concentration was 1 x = 0.13 ppm with a standard deviation of s1 = 0.04 ppm. In n2 = 31 samples from a location...
Wednesday, November 7, 2012 at 3:20am

statistics.. URGENT!! PLZ!!
In a learning experiment, untrained mice are placed in a maze and the time required for each mouse to exit the maze is recorded. The average time for untrained mice to exit the maze is µ = 50 seconds and the standard deviation of their times is ? = 16 seconds. 64 ...
Tuesday, November 6, 2012 at 5:33pm

Statistics Please help!
A company claims that cancer patients using drug X will live at least 8 more years. n=25 = 8.5 year s = 1.5 year a) Test at a=.01 b) Give the CIE at 95%
Tuesday, November 6, 2012 at 3:53pm

Statistics
The residual sum of the squares is the numerator portion of the formula for the variance of y about the regression line. True False
Tuesday, November 6, 2012 at 9:57am

Statistics
To conduct a valid regression analysis, both x and y must be approximately normally distributed. True False
Tuesday, November 6, 2012 at 9:56am

Math Statistics
The mean height of Pat, Dex, Allan, Dan and Roy is 68 inches. If George is included in the group, the mean height becomes 67 inches. How tall is George?
Tuesday, November 6, 2012 at 4:53am

Math Statistics
Kesha's mean grade for the first two terms was 74. What grade must she get in the third term to get an exact passing average of 75?
Tuesday, November 6, 2012 at 4:15am

Math Statistics
Kesha's mean grade for the first two terms was 74. What grade must she get in the third term to get an exact passing average of 75?
Tuesday, November 6, 2012 at 4:14am

Math Statistics
The height of four students are as follows: Pat - 112, Gerald - 123, Mark -100, Ricky - 125, Roy - 143. If Jon is included, the mean height would be 110. What is Jon's Height?
Tuesday, November 6, 2012 at 4:12am

statistics
Here are 6 measurements of the electrical conductivity of a iron rod: 10.08, 9.89,10.05,10.16,10.21,1011 The iron rod is supposed to have conductivity 10.1. Do the measurements give good evidence that the true conductivity is not 10.1? The 6 measurements are an SRS from the ...
Monday, November 5, 2012 at 11:01pm

statistics
Do you want to own your own candy store? Wow! With some interest in running your own business and a decent credit rating, you can probably get a bank loan on startup costs for franchises such as Candy Express, The Fudge Company, Karmel Corn, and Rocky Mountain Chocolate ...
Monday, November 5, 2012 at 11:00pm

statistics
The iron rod is supposed to have conductivity 10.1. Do the measurements give good evidence that the true conductivity is not 10.1?
Monday, November 5, 2012 at 10:57pm

Statistics
To conduct a valid regression analysis, both x and y must be approximately normally distributed. True False
Monday, November 5, 2012 at 10:10pm

Statistics
The residual sum of the squares is the numerator portion of the formula for the variance of y about the regression line. True False
Monday, November 5, 2012 at 10:09pm

statistics
He method of tree ring dating gave the following years A.D. for an archaeological excavation site. Assume that the population of x values has an approximately normal distribution. 1222, 1243, 1257, 1285, 1268, 1316, 1275, 1317, 1275 (a) Use a calculator with mean and standard ...
Monday, November 5, 2012 at 10:00pm

statistics
Total plasma volume is important in determining the required plasma component in blood replacement therapy for a person undergoing surgery. Plasma volume is influenced by the overall health and physical activity of an individual. Suppose that a random sample of 48 male ...
Monday, November 5, 2012 at 9:59pm

Statistics
Bone mineral density (BMD) was measured for seven postmenopausal women: 1.7, 1.6, 1.4,1.3, 2.1, 2.3, 1.5 g/cm2. Find a 99% confidence intervar for the mean BMD.
Monday, November 5, 2012 at 5:19pm

statistics
According to the book Are you Normal?,40% of all US adults try to pad their auto insurance claims to cover their deductible. Your office has just received 128 in insurance claims to be processed in the next few days, what is the probability that fewer than 45 of the claims ...
Monday, November 5, 2012 at 11:07am

Statistics
From a recent statistical analysis for the last five years, on an average there are 4 (major) air accidents per month in the world. Let X be the number of air accidents occurred in a randomly selected month. It is known that X ~ Poisson() approximately, where the ...
Monday, November 5, 2012 at 11:02am

Statistics
A random sample of 250 men yielded 175 who said they'd ridden a motorcycle at some time in their lives, while a similar sample of 215 women yielded only 43 that had done so. Find a 99% confidence interval for the difference between the proportions of men and women who have...
Monday, November 5, 2012 at 9:53am

Statistics
A random sample of 384 people in Dalto City, a mid-sized city, revealed 112 individuals who work at more than one job. A second random sample of 432 workers from East Dettweiler, another mid-sized city, found 91 people who work at more than one job. To conduct a significance ...
Monday, November 5, 2012 at 9:52am

statistics
The U.S. Dairy Industry wants to estimate the mean yearly milk consumption. A sample of 20 people reveals the mean yearly consumption to be 72 gallons with a standard deviation of 15 gallons. What is the 99% confidence interval for the population mean?
Sunday, November 4, 2012 at 6:06pm

statistics
In one town 76% of adults have health insurance, find the probability that 8 adults selected at random from the town all have health insurance. would it be unusual to select 8 people and find they all have health insurance. and why?
Sunday, November 4, 2012 at 4:09pm

statistics
A random sample of 250 men yielded 175 who said they'd ridden a motorcycle at some time in their lives, while a similar sample of 215 women yielded only 43 that had done so. Find a 99% confidence interval for the difference between the proportions of men and women who have...
Sunday, November 4, 2012 at 2:17pm

statistics
A random sample of 384 people in Dalto City, a mid-sized city, revealed 112 individuals who work at more than one job. A second random sample of 432 workers from East Dettweiler, another mid-sized city, found 91 people who work at more than one job. To conduct a significance ...
Sunday, November 4, 2012 at 2:16pm

Statistics
A random sample of 384 people in a mid-sized city (city one) revealed 112 individuals who worked at more than one job. A second random sample of 432 workers from another mid-sized city (city two) found 91 people who work at more than one job. Find a 99% confidence interval for...
Sunday, November 4, 2012 at 12:03pm

Statistics
You have two independent samples of size 24 and 27. You conduct a hypothesis test and obtain a p-value. Using the conservative method what would you use for the degrees of freedom for comparison? 24 27 23 26 49
Sunday, November 4, 2012 at 11:52am

Statistics
In recording the self-reported lengths of a particular body part in a sample of male undergraduates, the largest was claimed to be 20 cm—a full 3 standard deviations from the mean length for the sample. The shortest alleged length was only 10 cm, which was equivalent to ...
Saturday, November 3, 2012 at 11:31pm

Math,Statistics
Johnny suffers from Flu an average of 5 times per week. However, Tony claims that Johnny rarely suffers from fewer than 15 bouts flu per week. If Johnny has been suffering from flu for 180 weeks, at a minimum, how many of those weeks has he suffered from fewer ...
Saturday, November 3, 2012 at 11:25pm

statistics
The average age for licensed drivers in the county is μ 40.3 years with a standard deviation of 13.2 years. a. A researcher obtained a random sample of n 16 parking tickets and computed an average age of M 38.9 years for the drivers. Compute the z...
Saturday, November 3, 2012 at 9:40pm

AP Statistics
Your mathematics instructor claims that, over the years, 88% of his students have said that math is their favorite subject. In this year's class, however, only 21 out of 32 students named math as their favorite class. The instructor decides to construct a confidence ...
Saturday, November 3, 2012 at 2:29pm

AP Statistics
We guess, based on historical data, that 30% of graduating high-school seniors in a large city will have completed a first-year calculus course. What's the minimum sample size needed to construct a 95% confidence interval for a proportion with a margin of error of 2.5%? ...
Saturday, November 3, 2012 at 2:29pm

MATH,statistics
At a recent scotch-tasting party, 20 faculty members and their (opposite sex) spouses were guzzling it back pretty well. One person quite correctly noticed that the women seemed to be drinking more than the men. If the mean number of drinks had by the men was 5, and that for ...
Friday, November 2, 2012 at 3:38pm

statistics
A leading company chemically treats its product before packaging. The company monitors the weight of product per hour that each machine treats. An SRS of 90 hours of production data for a particular machine is collected. The measured variable is in pounds. (a) Using the data ...
Friday, November 2, 2012 at 3:46am

statistics
The purchasing department has suggested that all new computer monitors for your company should be a new design. You want data to assure you that employees will like the new monitors. The next 20 employees needing a new computer are the subjects for an experiment. (a) Label the...
Friday, November 2, 2012 at 3:45am

statistics
the monthly sales at a computer store have mean of $25,000 and a standard deviation of $4,000. profits are calculated by multiplying sales ny 30% and subtracting fixed cost of $60,000. find the mean and standard deviation of monthly profit
Thursday, November 1, 2012 at 11:02pm

Statistics
Opinion polls find that 13% of Americans "never have time to relax." If you take an SRS of 543 adults, the approximate distribution of the number in your sample who say they never have time to relax will be binomial with parameters: n= p=
Thursday, November 1, 2012 at 10:35pm

Statistics
Suppose the mean height of a population is 65 inches with a standard deviation of 1.5 inches. What is the z value for a height (x) of 67 inches?
Thursday, November 1, 2012 at 8:33pm

Statistics
What critical t value would be needed to construct a 90% confidence interval on a sample of size 22? 1.717 1.323 2.080 1.321 1.721
Thursday, November 1, 2012 at 11:25am

statistics
Let x be a continuous random variable that is normally distributed with a mean of 65 and a standard deviation of 15. Find the probability that x assumes a value less than 44.
Wednesday, October 31, 2012 at 10:05pm

statistics
An archer normally hits the target with probability of 0.7. She hires a new coach for a series of special lessons. After the lessons she hits the target in eleven out of fourteen attempts.
Wednesday, October 31, 2012 at 9:34pm

AP Statistics
A Kansas University research station wishes to investigate if a new variety of wheat is more resistant to a disease than an old variety. It is known that this disease strikes approximately 15% of all plants of the old variety. A field experiment was conducted, and of 120 new ...
Wednesday, October 31, 2012 at 11:22am

AP Statistics
A local McDonald's manager will return a shipment of hamburger buns if more than 10% of the buns are crushed. A random sample of 81 buns finds 13 crushed buns. A 5% significance test is conducted to determine if the shipment should be accepted. The p value for this ...
Wednesday, October 31, 2012 at 11:21am

statistics
Based on data from a statistical abstract, only about 12% of senior citizens (65 years old or older) get the flu each year. However, about 24% of the people under 65 years old get the flu each year. In the general population, there are 15% senior citizens (65 years old or ...
Tuesday, October 30, 2012 at 11:09am

Statistics
An instant lottery game gives you probability 0.023 of winning on any one play. Plays are independent of each other. If you play 2 times, the probability that you win on one or more of your plays is about? (±0.0001) Thank you!
Monday, October 29, 2012 at 8:47pm

statistics
A researcher is interested in estimating the average salary of teachers in a large urban school district. She wants to be 95% confident that her estimate is correct. If the standard deviation is $1050 (σ = 1050), how large of a sample is needed to be accurate within $200...
Monday, October 29, 2012 at 4:01pm

Statistics
A university has an exclusive agreement with the coffee chain Monobeans. Several students and faculty complained about their lack of baked goods. Looking for a better provider of carbs and caffiene, the university management rents out for one trial semester a space within a ...
Monday, October 29, 2012 at 3:57pm

AP Statistics
As the degrees of freedom for the t-distribution increase, the distribution approaches the value of zero for the mean. the t-distribution. the normal distribution. the F distribution. I'm thinking C...
Monday, October 29, 2012 at 3:28pm

AP Statistics
When finding a confidence interval for a population mean based on a sample of size 11, which assumption is made? The standard deviation is fixed. The sampling distribution of z is normal. The sampling distribution of the sample means is approximately normal. There is no ...
Monday, October 29, 2012 at 3:28pm

Statistics[Math]
Construct a histogram for following frequency distribution : Class-intervals Frequency 0-4 5 5-9 8 10-14 12 15-19 9 20-24 4
Monday, October 29, 2012 at 12:28am

statistics
Two boats, the Prada (Italy) and the Oracle (U.S.A.), are competing for a spot in the upcoming America’s Cup race. They race over a part of the course several times. Below are the sample times in minutes. Assume the population standard deviations are not the same. At the...
Sunday, October 28, 2012 at 8:31pm

statistics/probability
A game consists of tossing two coins, first a dime and then a nickel. For each coin which comes up a head you win the value of the coin. For each coin which comes up a tail you get nothing. {HH,HT,TH,TT} - each outcome with probability .25 - winnings are 15,10,5,0 a) Find the ...
Sunday, October 28, 2012 at 7:49pm

Statistics
The manager of the customer service division of a consumer electronics company was interested in determining whether customers who had purchased a DVD player over the past 12 months were satisfied with their products. Using the warranty cards submitted after purchases, the ...
Saturday, October 27, 2012 at 12:34am

statistics
determine whether the following formula is a probability distribution P(X)=X/20 for X=1,4,7 AND P(X)=X+0.1 for X=0.24,0.26,0.15
Saturday, October 27, 2012 at 12:02am

statistics
A lottery offers one $800 prize, one $400 prize, and ten $80 prizes. One thousand tickets are sold at $3 each. Find the expectation if a person buts two tickets. Assume that each ticket can win more than one prize.
Friday, October 26, 2012 at 11:55pm

Statistics
Your mathematics instructor claims that, over the years, 88% of his students have said that math is their favorite subject. In this year's class, however, only 21 out of 32 students named math as their favorite class. The instructor decides to construct a confidence ...
Friday, October 26, 2012 at 1:57pm

Statistics
Your mathematics instructor claims that, over the years, 88% of his students have said that math is their favorite subject. In this year's class, however, only 21 out of 32 students named math as their favorite class. The teacher decides to conduct a test of the hypothesis...
Friday, October 26, 2012 at 1:56pm

Statistics
A Kansas University research station wishes to investigate if a new variety of wheat is more resistant to a disease than an old variety. It is known that this disease strikes approximately 15% of all plants of the old variety. A field experiment was conducted, and of 120 new ...
Friday, October 26, 2012 at 1:52pm

Statistics
A local McDonald's manager will return a shipment of hamburger buns if more than 10% of the buns are crushed. A random sample of 81 buns finds 13 crushed buns. A 5% significance test is conducted to determine if the shipment should be accepted. The p value for this ...
Friday, October 26, 2012 at 1:50pm

Statistics
What critical t value would be needed to construct a 90% confidence interval on a sample of size 22? 1.717 1.323 2.080 1.321 1.721
Friday, October 26, 2012 at 1:28pm

Statistics
As the degrees of freedom for the t-distribution increase, the distribution approaches the value of zero for the mean. the t-distribution. the normal distribution. the F distribution.
Friday, October 26, 2012 at 1:23pm

Statistics
When finding a confidence interval for a population mean based on a sample of size 11, which assumption is made? The standard deviation is fixed. The sampling distribution of z is normal. The sampling distribution of the sample means is approximately normal. There is no ...
Friday, October 26, 2012 at 1:23pm

Statistics
A set of X and Y scores has SSx=10, SSY=20, and SP=8, what is the slope for the regression equation? a, 8/10 b, 8/20 c, 10/8 d, 20/8
Friday, October 26, 2012 at 3:55am

Statistics
For the regression equation, Y=bX+a, which of the following X,Y points will be on the regression line? a, a,b b, b,a c, 0,a d, 0,b
Friday, October 26, 2012 at 3:54am

statistics
A set of X and Y scores has Mx=4, SSx=10, MY=5, SSY=40, and SP=40. What is the regression equation for predicting Y from X? a, =0.25X-4 b, =4X+4 c, =X-6 d, =4X-11
Friday, October 26, 2012 at 3:54am

Statistics
A physical fitness association is including the mile run in its secondary-school fitness test. The time for this event for boys in secondary school is known to possess a normal distribution with a mean of 460 seconds and a standard deviation of 40 seconds. The fitness ...
Wednesday, October 24, 2012 at 11:09pm

statistics!
The following data represents the body mass index in a random group of twelve diabetic patients in a clinic. 18, 28, 31, 14, 25, 21, 22, 28, 35, 29, 27, 22. What is the z score of the person with the lowest and highest body mass index?
Wednesday, October 24, 2012 at 10:11pm

Statistics
a city law-enforcement official has stated that 20% of the items sold by pawn shops within the city have been stole. Ralph has just purchased 4 items from one of the city's pawn shops. Assuming that the official is correct, and for x = the number of ralph's purchases ...
Wednesday, October 24, 2012 at 9:15pm

statistics!
1) Entry to a certain University is determined by a national test. The scores on this test are normally distributed with a mean of 500 and a standard deviation of 100. Tom wants to be admitted to this university and he knows that he must score better than at least 70% of the ...
Wednesday, October 24, 2012 at 7:54pm

statistics
suppose x is a uniform random variable with c=30 and d=80 find the probability that a randomly selected observation exceeds 50 this is the direct question, i have no idea how to work this problem, please help
Wednesday, October 24, 2012 at 5:24pm

statistics
A university wants to estimate the average distance that commuter students travel to get to class with an error of ±3 miles and 90 percent confidence. What sample size would be needed, assuming that distances are normally distributed with a range of X = 0 to X = 50 ...
Wednesday, October 24, 2012 at 10:19am

Statistics
In practical use, oral contraceptives have a 5% chance of failing. If a doctor has 10 patients using oral contraceptives, what is the probability that at least 1 will get pregnant?
Tuesday, October 23, 2012 at 10:03pm

Statistics
A set of X and Y scores has SSx=10, SSY=20, and SP=8, what is the slope for the regression equation? a. 8/10 b. 8/20 c. 10/8 d. 20/8 For the regression equation, Y=bX+a, which of the following X,Y points will be on the regression line? a. a,b b. b,a c. 0, a d. 0, b
Monday, October 22, 2012 at 7:54pm

statistics
According to American Airlines, Flight 215 from Orlando to Los Angeles is on time 90% of the time. Suppose 150 flights are randomly selected. Find the probability that few than 125 flights are on time.
Monday, October 22, 2012 at 12:59am

Statistics
In Professor White’s statistics course the correlation between the students’ total scores before the final examination and their final examination scores is r = 0.9. The pre-exam totals for all students in the course have mean 275 and standard deviation 50. The final...
Sunday, October 21, 2012 at 11:08pm

Statistics
The null and alternate hypotheses are: H0: μ1 = μ2 H1: μ1 ≠ μ2 A random sample of 15 items from the first population showed a mean of 50 and a standard deviation of 5. A sample of 12 items for the second population showed a mean of 46 and a standard ...
Sunday, October 21, 2012 at 8:28pm

statistics
If other factors are held constant, how does increasing the number of scores in each sample affect the value of the independent measures t statistic and the likelihood of rejecting the null hypothesis?
Sunday, October 21, 2012 at 8:06pm

statistics
I need help with p for a hypothesis test for normal distribution.
Saturday, October 20, 2012 at 9:15pm

statistics
Suppose you wanted to test your ESP using an ordinary deck of 52 cards, which has 26 black and 26 red cards. You have a friend shuffle the deck and draw cards at random, replacing the card and reshuffling after each guess. You attempt to guess the color of each card. What is ...
Saturday, October 20, 2012 at 3:13pm

statistics
Suppose a shipment of 500 machine parts contains 62 defective and 438 non-defective machine parts. From the shipment you take a random sample of 25. You are interested in the number of defective machine parts out of 25 trials and corresponding probabilities. I believe the ...
Saturday, October 20, 2012 at 2:48pm

Stats
Cans of regular Coke are labeled as containing 12. Statistics students weighted the content of 10 randomly chosen cans, and found the mean weight to be 12.1. Assume that cans of Coke are filled so that the actual amounts are normally distributed with a mean of 12 and a ...
Saturday, October 20, 2012 at 12:09pm

Math Statistics
The table below shows Rico’s grades during the third term in four subjects. Subject Units Grade Math 1.5 98 Science 2 97 English 1.5 95 A.P. 1 99 What was Rico’s average grade in the four subjects?
Friday, October 19, 2012 at 11:30pm

Math Statistics
Are there any advantages or disadvantages to using data that follow a normal distribution?
Friday, October 19, 2012 at 10:47pm

statistics
Given the length an athlete throws a hammer is a normal random variable with mean 50 feet and standard deviation 5 feet, what is the probability he throws it between 50 feet and 60 feet?
Friday, October 19, 2012 at 7:15pm

Math Statistics
Czarina is working part time at a pastry shop baking cupcakes. If she works for 30 hours in one week on the average, how many hours a day does she work if she works 5 days a week?
Friday, October 19, 2012 at 9:01am

Math Statistics
What is the difference between "weighted mean" and "arithmetic mean?"
Friday, October 19, 2012 at 8:23am

Math Statistics
Czarina is working part time at a pastry shop baking cupcakes. If she works for 30 hour in one week on the average, how many hours a day does she work?
Friday, October 19, 2012 at 8:20am

nutrition
Jonathan, a two-and-a-half-year-old, lives with his mother and brothers at his grandmother's house in Chicago. His mother, Anita, works at a pharmacy to support the family. Jonathan spends his days at home with his grandmother. While Anita works, his grandmother brings the...
Thursday, October 18, 2012 at 8:04pm

statistics
in a survey 15% of the student said they don't own computers if 75 didn't own computers how many took the survey
Thursday, October 18, 2012 at 9:42am

Statistics
Thirty-two students took a 50-item Biology test. The average score obtained is 42. The next day, three students who were absent took the test and obtained 35, 39 and 43. What is the average score of the 35 students?
Wednesday, October 17, 2012 at 6:52pm

statistics
For each of the following questions, decide whether or not the sample data can be used to construct a confidence interval. How do I go about determining if the sample data can be used to construct a confidence interval? Example: To help consumers assess the risks they are ...
Wednesday, October 17, 2012 at 11:50am

statistics
Consider a population with µ=93.3 and σ=5.27. (A) Calculate the z-score for x=94.9 from a sample of size 12. (B) Could this z-score be used in calculating probabilities using Table 3 in Appendix B of the text? Why or why not?
Wednesday, October 17, 2012 at 8:27am

statistics
A group of 200 students takes the Kaplan course in hopes that it will improve their SAT scores above the national mean of 500 on the math section. The population standard deviation of the SAT is known to be 100. Use an alpha level of .05 when answering the following questions...
Tuesday, October 16, 2012 at 8:12pm

statistics
First graders who misbehave in school may be more likely to be regular smokers as young adults according to a new study presented in the July 2004 issue of the American Journal of Epidemiology. After following a group of U.S. first graders for 15 years, it was found that among...
Tuesday, October 16, 2012 at 6:15pm

statistics
Will is convinced that there is a relationship between a woman's age and how old she acts. In order to test this , I asked the women in my family their ages and then gave them an age acting test. Check to see if wills hypothesis is true using p value 0.5. You mist indicate...
Tuesday, October 16, 2012 at 12:33am

Math Statistics
I need to find the critical value of what I have here so far, and I am stuck can someone please help? Percent of children depressed: 4.3% 1250= n 4.3/100= s/1250 53.75= sample mean n=sample size After, mid 2010: Percent of children depressed: 5% 100= n 5/100= s/100 5= sample ...
Monday, October 15, 2012 at 10:08pm

statistics
3. Consider selecting a starting line up for an intermural 6-on-6 indoor soccer team where you are required to have 4 students and 2 faculty on the court at all times. As everyone on your team have equal skills, you decide to randomly assign members to your starting lineup ...
Monday, October 15, 2012 at 9:50pm

statistics
If total items is 7500 and 300 are tested what's percentage that 25 are bad?
Monday, October 15, 2012 at 8:35pm

Statistics
Over a period of about nine months, 1,353 women reported the timing of each of their menstrual cycles. For the first cycle reported by each woman, the mean cycle time was 28.86 days, and the standard deviation of the 1,353 times was 4.24 days. (a) Construct a 92% confidence ...
Monday, October 15, 2012 at 8:08pm

6th grade math Statistics and Graphs
If I were to do a survey on how many students have pets in my class should I include the zero amount of kids that didn't have pets in my calcualtion?
Monday, October 15, 2012 at 6:02pm

statistics
random sample of n = 16 scores is selected from a normal distribution with a mean of μ = 50 and standard deviation of σ = 10. a. what is the probability that the sample mean will have a value between 45 and 55? b. what is the probability that the sample mean will ...
Monday, October 15, 2012 at 1:20am

Elementary Statistics
Compare the 95% and 99% confidence intervals for the hours of sleep a student gets. Explain the difference between these intervals and why this difference occurs.
Sunday, October 14, 2012 at 11:50pm

Statistics
You have a population that has a mean of 100 and a standard deviation of 15. You randomly draw 100 people out of this population and record the mean score. You repeat the process a large number of times recording the mean score for each sample you draw. What will be the ...
Sunday, October 14, 2012 at 9:41pm

Behavioral Statistics
You have a population that has a mean of 100 and a standard deviation of 15. You randomly draw 100 people out of this population and record the mean score. You repeat the process a large number of times recording the mean score for each sample you draw. What will be the ...
Sunday, October 14, 2012 at 9:07pm

statistics
A researcher wishes to estimate with 95% confidence the proportion of adults who have high speed internet access. Her estimate must be accurate within 4% of the true proportion. 1. Find the minimum sample size needed using a prior study that found that 48% of the respondents ...
Sunday, October 14, 2012 at 6:04pm

Sociololgy
What is the main difference between parametric and nonparametric statistics?
Sunday, October 14, 2012 at 3:50pm

statistics
What is wrong with the following statements? a) For a large n, the distribution of observed values will be approximately Normal b) 68-95-99.7 rule says that "x bar" should be within m (mean) +/- 2 SD (standard deviation) about 95% of the time c) The central limit ...
Sunday, October 14, 2012 at 12:14pm

Statistics
Assume that the average annual salary for a worker in the United States is 300,000- and that the annual salaries For Americans are normally distributed with a standard deviation equal to $7,000. Find the following: A. What percentage of Americans earn below $22,000? B. What ...
Sunday, October 14, 2012 at 12:10pm

statistics
given the 95% confidence interval (6.214, 7.686), interpret
Sunday, October 14, 2012 at 12:51am

statistics
A vertical line is drawn through a normal distribution at z = 0.50, and separates the distribution into two sections. What proportion of the distribution is in the larger section? a. 0.6915 b. 0.3085 c. 0.1915 d. 0.3830
Sunday, October 14, 2012 at 12:09am

statistics
What z-score values form the boundaries for the middle 60% of a normal distribution? a. z = +0.25 and z = –0.25 b. z = +0.39 and z = –0.39 c. z = +0.52 and z = –0.52 d. z = +0.84 and z = –0.84
Sunday, October 14, 2012 at 12:08am

Statistics
John drives to work each morning and the trip takes an average of μ = 38 minutes. The distribution of driving times is approximately normal with a standard deviation of σ = 5 minutes. For a randomly selected morning, what is the probability that John’s drive to ...
Sunday, October 14, 2012 at 12:07am

Statistics
If you roll two dice what is the probablity of getting one 2? I think the answer is 1/6 but I'm not sure
Saturday, October 13, 2012 at 12:36pm

statistics
A researcher wants to study the spending habits of customers of a local shopping mall. The mall manager claims that the average spending per customer is $70, but the researcher believes that the average is less than $70. A simple random sample of 350 shoppers is obtained. The ...
Saturday, October 13, 2012 at 10:12am

Statistics (Math)
A government report looked at the amount borrowed for college by students who graduated in 2000 and had taken out student loans. The mean amount was = $ 17 , 776 and the standard deviation was s = $12,034. The quartiles were Q 1 = $9900, M = $15,532, and Q 3 = $22,500. The ...
Saturday, October 13, 2012 at 3:27am

statistics
Five percent of all items sold by a mail-order company are returned by customers for a refund. Find the probability that of two items sold during a given hour by this company both will be returned for a refund (round to four decimal places).
Friday, October 12, 2012 at 7:24pm

Statistics
A total of 16 mice are sent down a maze, one by one. From previous experience, it is believed that the probability a mouse turns right is .38 a) What is the probability that exactly 8 of these 16 mice turn right? b) What is the probability that 8 or fewer turn right? c) What ...
Friday, October 12, 2012 at 2:58pm

statistics - probability
A total of 16 mice are sent down a maze, one by one. From previous experience, it is believed that the probability a mouse turns right is .38 a) What is the probability that 8 or fewer turn right? b) What is the probability that 8 or more turn right? c) What is the probability...
Friday, October 12, 2012 at 2:01pm

statistics
7. Give and interpret the 95% confidence interval for the hours of sleep a student gets
Thursday, October 11, 2012 at 9:46am

Statistics
25 students test grades (possible scores 0 to 100)has a standard deviation of 15. What logically follows???
Wednesday, October 10, 2012 at 11:13pm

statistics
The heights of women aged 20 to 29 follow approximately the N (64, 4) distribution. Men the same age have heights distributed as N (69.8, 1.1). What percent of young women are taller than the mean height of young men?
Wednesday, October 10, 2012 at 10:57pm

Statistics
The number of traffic accidents per day on a certain section of highway is thought to be Poisson distributed with a mean equal 2.19. Based on this, how many traffic accidents should be expected during a week long period? a. 15.33 b. 10.95 c. approximately 10.36 d. ...
Wednesday, October 10, 2012 at 10:44pm

Statistics
A sample of 50 values produced the following summary statistics: Q1 = 10, Q2 = 14.6, Q3 = 16.7 and x = 15.3. Based on this information, the left and right ends of the box in a box and whisker plot are, respectively, a. 10 and 14.6 b. 14.6 and 16.7 c. 10 and 16.7 d. 5.3 and 32....
Wednesday, October 10, 2012 at 10:43pm

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