Thursday
July 30, 2015

Homework Help: Math: Statistics

Recent Homework Questions About Statistics

Statistics
The time it takes a technician to fix a computer problem is exponentially distributed with a mean of 15 minutes. what is the probability that a). it will take a technician less than 10 minutes to fix a computer problem? b) it will take a technician between 10 to 15 minutes to ...
Sunday, March 15, 2015 by Leo Elvis

Statistics
the age of costumers for a particular retail store follows a normal distribution with a mean of 37.5 years and a standard deviation of 7.6 years. what is the probability that the next costumer who enters the store will be less than 42 years old?
Sunday, March 15, 2015 by Leo Elvis

Statistics
in 2000, the averages change of tax preparation was $95. Assuming a normal distribution and a standard deviation of $10. What proportion of tax preparation fees were more than $95.
Sunday, March 15, 2015 by Leo Elvis

Statistics
How many different ways can you put 3 distinguishable things in 10 boxes?
Saturday, March 14, 2015 by Bob

statistics
A credit card company estimates that the average credit card balance of Americans is $3,210. A statistics student wants to know whether this is true for citizens of her home town. Which hypothesis test would be most appropriate for addressing this question? One sample z-test ...
Saturday, March 14, 2015 by madi

statistics
A clinical trial tests a method designed to increase the probability of conceiving a girl. In the study 395 babies were born, and 316 of them were girls. Use the sample data to construct a 99% confidence interval estimate of the percentage of girls born. Based on the result, ...
Friday, March 13, 2015 by slomomo

Statistics
80. Florida State University has 14 statistics classes scheduled for its Summer 2013 term. One class has space available for 30 students, eight classes have space for 60 students, one class has space for 70 students, and four classes have space for 100 students. a. What is the...
Friday, March 13, 2015 by Howard

Statistics - Can anybody help me?
A Particular pain relieving medicine has a decay rate of 24% an hour. A patient was given a dose of the medicine 5 hours ago and there is currently 74mg of the medicine in the patients bloodstream. Q: What was the Origional dose of the medicine? ________ milligrams. Q How long...
Friday, March 13, 2015 by Cindy

Statistics
A Particular pain relieving medicine has a decay rate of 24% an hour. A patient was given a dose of the medicine 5 hours ago and there is currently 74mg of the medicine in the patients bloodstream. Q: What was the Origional dose of the medicine? ________ milligrams. Q How long...
Friday, March 13, 2015 by Cindy

Statistics
Good Afternoon, Hope everyone will have a nice weekend. I am sorry to bother you all, but I am failing statistic. Can someone give me an example of this and example of a regression hypothesis. Thank you
Friday, March 13, 2015 by mary ann

statistics/probability
An engineer is going to redesign an ejection seat for an airplane. The seat was designed for pilots weighing between 130 lb and 181 lb. The new population of pilots has normally distributed weights with a mean of 135 and a standard deviation of 25.1 lb. If a pilot is randomly ...
Thursday, March 12, 2015 by slomomo

statistics
The mean (μ) of the scale is 83 and the standard deviation (σ) is 10. Assuming that the scores are normally distributed, what is the PROBABILITY that a score falls below 72?
Thursday, March 12, 2015 by chris

statistics
The average age of doctors in certain hospital is 43 years old. Suppose distribution of ages is normal and the standard deviation is 8.0 years. If 25 doctors is chosen at random for a committee, find the probability the average age for those doctors is less than 43.8 years. ...
Wednesday, March 11, 2015 by stuart joel

statistics
A casting director wishes to find one male and one female to cast is his play. If he plans to audition 5 males and 7 females, in how many different ways can this be done? DO NOT put a comma in your response.
Wednesday, March 11, 2015 by jesse

Statistics
Shopping Outlet A shopping outlet estimates the probability distribution of the number of stores shoppers actually enter as shown in the table below. x 0 1 2 3 4 p(x) 0.05 0.35 0.25 0.20 0.15 What is the probability that shoppers are just window shopping and not entering any ...
Wednesday, March 11, 2015 by Anon

Statistics
In the following problem, check that it is appropriate to use the normal approximation to the binomial. Then use the normal distribution to estimate the requested probabilities. More than a decade ago, high levels of lead in the blood put 87% of children at risk. A concerted ...
Tuesday, March 10, 2015 by Leatha

Elementary Statistics
"Scores on the Wechsler IQ test approximate a normal curve with a mean of 100 and a standard deviation of 15. b. What percentage of IQ scores are below 74?" I've been working at this for a while now, but when I solve for the z-score, I keep getting a negative ...
Tuesday, March 10, 2015 by Nicole

statistics
Z-test. How to find critical value for one tail test?
Tuesday, March 10, 2015 by Anonymous

statistics - can someone please Help me
I have tried for days to figure out how to work this problem. Please help show me how to find the answer. A particular radioactive isotope decays from 210 mg to 182.7 mg in 15 days. Find the half life of the isotope. I can not find any problem that is similar. everything i ...
Tuesday, March 10, 2015 by Tina

statistics
How to find p value? If test statistic is -0.37, will the p value be 0.3557?
Tuesday, March 10, 2015 by Anonymous

statistics
I have tried for days to figure out how to work this problem. Please help show me how to find the answer. A particular radioactive isotope decays from 210 mg to 182.7 mg in 15 days. Find the half life of the isotope.
Tuesday, March 10, 2015 by Tina

statistics
A jar contains 3 nickels and 2 dimes. You reach in and randomly select 2 coins. Let x represent the value of the two coins in cents. Find the expected value and standard deviation of x
Tuesday, March 10, 2015 by Ashley

statistics
Determine whether the description corresponds to an observational study or an experiment. Research is conducted to determine if there is a relation between kidney function in adults and childhood-onset diabetes.
Tuesday, March 10, 2015 by slomomo

statistics
Based on a study of IQs of men and women who play chess competitively, a researcher concludes that playing chess causes people to become smarter. Do you agree with this conclusion?
Tuesday, March 10, 2015 by slomomo

Statistics
A history class is comprised of 5 female and 8 male students. If the instructor of the class randomly chooses 8 students from the class for an oral exam, what is the probability that 2 female students and 6 male students will be selected? Round your answer to decimal places.
Tuesday, March 10, 2015 by Ryan

problem and statistics
In a random sample of 10 on-line statistics students, information was collected about their minutes studied and their chapter test scores. X is the minutes studied, and Y is the test score. x : {20,30,45,60,80,90,45,120,90,70} y: {50,45,55,70,80,90,80,100,95,85} Is this ...
Monday, March 9, 2015 by Zikera

statistics
An online site presented this question, 'Would the recent norovirus outbreak deter you from taking a cruise?' Among 34,327 people who responded, 66% answered 'yes'. Use the sample data to construct a 95% confidence interval estimate for the proportion of the ...
Monday, March 9, 2015 by slomomo

Statistics
In the week before and the week after a holiday, there were 12,000 total deaths, and 5916 of them occurred in the week before the holiday. a. Construct a 95% confidence interval estimate of the proportion of deaths in the week before the holiday to the total deaths in the week...
Monday, March 9, 2015 by slomomo

Healthcare Statistics
As a data collection specialist at the National Institutes of Health (NIH), you have been involved in a research study conducted over the past year. The study found that liver cancer rates per 100,000 males among cigarette smokers to nonsnmokers, in a major urban U.S. city, ...
Sunday, March 8, 2015 by Nancy

Statistics
What does p-hat mean
Sunday, March 8, 2015 by slomomo

Statistics
If a mother has three bananas, two pears, and two oranges, in how many different ways can she give the fruit to her daughter in one week, one piece of fruit per day?
Saturday, March 7, 2015 by Jenifer

statistics
In the population, the average IQ is μ = 100 with a standard deviation of σ = 15. A team of scientists wants to test a new medication to see if it has a positive effect on intelligence. A sample of n = 10 participants who have taken the medication has a mean of M = ...
Saturday, March 7, 2015 by sam

statistics
I need help, I am trying to figure out the critical value of my homework and I am having a great deal of trouble. if z= 1.69 p = .0455 What is the critical value(s) , is/are z =?
Saturday, March 7, 2015 by phyllys

statistics
The mean cost of domestic airfares in the United states rose to an all-time high of $385 per ticket
Saturday, March 7, 2015 by spha

Business Statistics
The following tables shows the hourly wages of all workers in a certain hospital. Determine the pearsonian coefficient of skewness (population data). Hourly wages frequency 90-99 5 100-109 9 110-119 5 120-129 7 130-139 5 140-149 3 My answers: mean = 116.56 s = 15.72 But i dont...
Saturday, March 7, 2015 by rianne

statistics
A coin mint has a specification that a particular coin has a mean weight of 2.5 g. A sample of 39 coins was collected. Those coins have a mean weight of 2.49491 g and a standard deviation of 0.01372 g. Use a 0.05 significance level to test the claim that this sample is from a ...
Saturday, March 7, 2015 by slomomo

statistics
Suppose IQ scores were obtained from randomly selected twins. For 20 such pairs of people, the linear correlation coefficient is 0.876 and the regression line is y-hat = 11,76 + 0.89x, where x represents the IQ score of the twin born second. Also,the 20x values have a mean of ...
Saturday, March 7, 2015 by slomomo

math/statistics
The data show the time intervals after an eruption (to the next eruption) of a certain geyser. Find the regression equation,letting the first variable be the independent (x) variable. Find the best predicated time of the interval after an eruption given that the current ...
Friday, March 6, 2015 by slomomo

Statistics
Identify the type I error and type II error that corresponds to the given hypothesis. The proportion of settled medical malpractice suits is 0.28 I have been working on this one for 3 hours and am doing something wrong, Please help!!
Friday, March 6, 2015 by slomomo

statistics
For an IQ test, we know the population mean = 100 and the standard deviation =16. We are interested in creating the sampling distribution when N = 64. (a) What does that sampling distribution of means show? (b) What is the shape of the distribution of IQ means and the mean of ...
Friday, March 6, 2015 by amanda

Statistics
If bird flu mortality in one sample of 100 is 20% and in another sample of 100 it is 30%. Is the difference in mortality rate is significant? Solve for the statistic value of Z at probability alpha level of 0.05. Please show your solution.
Friday, March 6, 2015 by Jolina Marie Pedron

statistics
A survey found that women's heights are normally distributed with mean 62.4 in and standard deviation 2.8 in. The survey also found that men's heights are normally distributed with a mean of 68.9 in. and standard deviation 2.8. Complete parts a through c below. a. Most...
Thursday, March 5, 2015 by slomomo

Statistics/Probability
A certain brand of candies have a mean weigh of 0.8576 g and a standard deviation of 0.0523. A sample of these candies came from a package containing 447 candies,and the package label stated the net weight is 381.3 g. (If every package has 447 candies, the mean weight of the ...
Thursday, March 5, 2015 by slomomo

Statistics/Probability
Assume that women’s heights are normally distributed with a mean given by μ = 63.4 in, and a standard deviation given by σ = 2.3 in. (a) If 1 woman is randomly selected, find the probability that her height is less than 64 in. (b) If 43 women are randomly ...
Wednesday, March 4, 2015 by slomomo

statistics/normal distribution
Find the area of the shaded region.The graph to the right depicts IQ scores of Adults (85-120), and those scores are normally distributed with a mean of 100 and a standard deviation of 15
Wednesday, March 4, 2015 by slomomo

Statistics Help
Express the confidence interval (0.024, 0.112) in the form of p-hat – E < p < p-hat + E = __< p < __ I don't understand how to perform this formula. Please help I am about to graduate and this is my last class, and I am struggling as I only know basic Math...
Wednesday, March 4, 2015 by slomomo

statistics/Help Please!!
In a sample of seven cars, each car was tested for nitrogen-oxide emissions (in grams per mile) and the following results were obtained:0.18, 0.12, 0.05, 0.19, 0.18,0.13, 0.15. Assuming that this sample is representative of the cars in use, construct a 98% confidence interval ...
Wednesday, March 4, 2015 by slomomo

statistics
one bag contains 4 white balls,2 black balls.another bag contains 3 white balls 5 black balls.if one ball is drawn from each bag. find that a) both are white? b) both are black? c)one is white and one is black?
Wednesday, March 4, 2015 by sagar

Statistics
. Given that x is a normal variable with mean m=110 and standard divation (r=12, find P(x=≤120
Wednesday, March 4, 2015 by Venita

Statistics
A random sample of state gasoline taxes is shown for 12 states. Use the data to estimate the true population mean gasoline tax with 90% confidence. Does your interval contain the national average of 0.21? assume normal distribution.
Tuesday, March 3, 2015 by Say

Statistics
find the probability that you will get a "sum" of 5 or greater in rolling two dice experiment. How do you do this?
Tuesday, March 3, 2015 by Tamera

businessmath
Statistics show that the sales force of a certain company successfully closed 986 sales out of 1,700 sales calls. What was their percent success rate? If needed, enter decimals rather than fractions. Do not enter the percent symbol in your answer.i need the answer now
Tuesday, March 3, 2015 by babysunshine

Statistics
so we will be having a quiz about hypotheses testing and i cant still figure out the difference between the null hypothesis with alternative hypothesis. PLEASE HELP ME DIFFERENTIATE THE TWO. And i still get confused between one tailed test and two tailed test.. what's the ...
Tuesday, March 3, 2015 by Ngiti

Statistics
what is the cost of a dinner when there is a 0 rating when y hat=1.6+2.9x
Monday, March 2, 2015 by Mark

Statistics
How does the standard deviation differ to of the sample mean x bar. Please help I'm confused
Monday, March 2, 2015 by Sam

statistics
The life spans of three randomly selected tires are  28,100  miles,  37,900  miles, and  33,000  miles. Using the empirical rule, find the percentile that corresponds to each life span.
Sunday, March 1, 2015 by Anonymous

statistics
Fewer young people are driving. In 1983, 87 percent of 19 year-olds had a driver's license. Twenty-five years later that percentage had dropped to 75 percent (University of Michigan Transportation Research Institute website, April 7, 2012). Suppose these results are based ...
Sunday, March 1, 2015 by soni

statistics
In a test of the effectiveness of garlic for lowering cholesterol, 44 subjects were treated with garic in a processed tablet form. Cholesorol levels were measured before and after the treament. the changes in their levels of LDL cholestorol (in mg/dL have a mean of 3.5 and a ...
Sunday, March 1, 2015 by slomomo

Statistics/check answer
If a population has a standard deviation σ of 18.2 units, what is the standard error of the mean if samples of size 25 are selected? Show all work. standard error of the mean = 0/sqrt(n) = 18.2/sqrt(25) = 18.2/5 =3.64 Answer 3.64
Sunday, March 1, 2015 by slomomo

statistics
Suppose for the same 3000 women, we also measured their weight. Suppose the data were again normally distributed. The average weight is 143 lbs., and the standard deviation is 30 lbs. Suppose the correlation between height and weight is r = +.69. What is the slope of the best-...
Sunday, March 1, 2015 by marie

Statistics
Suppose that the distance of fly balls hit to the outfield (in baseball)is normally distributed with a mean of 250 feet and a standard deviation of50 feet. a. If X = distance in feet for a fly ball, then X ~ _____(_____,_____) b. If one fly ball is randomly chosen from this ...
Sunday, March 1, 2015 by Gail

Statistics
How many different 9 letter code words can be made using the symbols %%%% &&& ++
Sunday, March 1, 2015 by Anonymous

Statistics
Science scores for high school seniors in the United States are normally distributed with a mean of 78 and a standard deviation of 10. Students scoring in the top 10% are eligible for a special prize consisting of a laptop and $2,000. What is the approximate cutoff score a ...
Saturday, February 28, 2015 by JOE

statistics
how to summarize statistic assumption
Saturday, February 28, 2015 by blue

statistics
If weight in the general population is normally distributed with an average of 160 and a standard deviation of 20 pounds, what is the probability of selecting someone who weights 120 or less or 170 or more pounds?
Friday, February 27, 2015 by candy

statistics
Determine the level of the confidence given the confidence coefficient z(α/2) for the following situation: z(α/2) = 1.96
Friday, February 27, 2015 by slomomo

Statistics
With a known population mean of 100, and a known standard of error of the mean of 7.5, what is the probability of selecting at random a sample whose mean is equal to 110 or greater?
Friday, February 27, 2015 by Veronica

statistics
historically, the average customer spends $8.53 for all TGP restaurants(u=8.53). If the population standard deviation is $1.06(o=1.06) and the data is normally distributed, find the probabiltiy that the sample mean will be within $.15 of the populaiton mean using a sample size...
Friday, February 27, 2015 by angela

statistics
Assume that the regression equation for the relationship between SAT scores and IQ scores is y = 9 +.105x. What would you expect the IQ score to be for the following individuals, given their SAT scores? Individual SAT Score IQ Score Susan 850 Sally 1175 Sam 1225 Sean 1050
Friday, February 27, 2015 by candy

Healthcare Statistics
What is the mode of this data set 22 27 32 32 35 35 36 37 38 42 48 52 53 54 55 55 55 58 59 62 62 63 64 65 65 65 67 69 75 84 I see four modes: 32, 35, 55, and 65 Would this be considered multimodal?
Friday, February 27, 2015 by Nancy

statistics
For classes of 273 students, find the mean and standard deviation for the number born on the 4th of July, Ignore leap years. For a class or 273 students, would two be an unusually high number who were born on the 4th of July? I don't know how to find how many out of 273 ...
Friday, February 27, 2015 by slomomo

statistics
A headline in a certain newspaper states that "most stay at first job less than 2 years." That headline is based on an online poll of 320 college graduates. Among those polled, 72% stayed at their first full-time job less than 2 years. a. Assuming that 50% is the ...
Friday, February 27, 2015 by slomomo

Statistics
The results of a nationwide survey show that 57.40% of college students have violated rules of alcohol use. The margin of error for the survey is 2.30%. What does this mean?
Friday, February 27, 2015 by Chelsea

Statistics
Among the population of criminal justice students, the average score on the final exam was 74, with a standard deviation of 11.6. What is the probability of randomly selecting a student who earned an A (90 or better)?
Friday, February 27, 2015 by Maddie

Statistics
1200 high school freshman were randomly selected for a national survey. Among survey participants, the mean grade-point average was 2.8, and standard deviation was 0.6. What is the margin of error, assuming a 95% confidence level?
Friday, February 27, 2015 by Isabel

Statistics
A criminologist is studying school violence, she selects a random sample of 25 adolescents aged 12 to 15 from a local middle school and asks the following,"How many times within the past school year have you been physically assaulted at school? She calculated the ...
Friday, February 27, 2015 by Elena

Statistics
Suppose we would like to estimate the mean amount of money spent on books by students in the fall semester. We have the following data from 400 randomly selected students: mean=$205 and s=$40. Assume that the amount spent on books by students is normally distributed. Compute a...
Friday, February 27, 2015 by Elena

Statistics
Let x and y be the amounts of time (in minutes) that a particular commuter must wait for a train on two independently selected days. Define a new random variable w by w = x + y, the sum of the two waiting times. The set of possible values for w is the interval from 0 to 2a (...
Friday, February 27, 2015 by Abbey

statistics
Heights of men on a baseball team have a bell-shaped distribution with a mean of 169 cm and a standard deviation of 9 cm. Using the empirical rule, what is the approximate percentage of the men between the following values? a. 151 cm and 187 cm. b. 160 cm and 178 cm. Please ...
Thursday, February 26, 2015 by slomomo

statistics
In a course there is a midterm exam, worth 40% of the course grade, and a final exam worth 60%. On the midterm the mean grade was 80 with a standard deviation of 10, and on the final the mean was 75 with a standard deviation of 15. The correlation between the two exams is 0.6...
Wednesday, February 25, 2015 by jess

STATISTICS
a team of 3 is to be chosen from 4 boys and 5 girls. if X is the random variable of the number of girls in the team find the Expected variable X. E(X)
Wednesday, February 25, 2015 by KALAN ENILEOHS

statistics/normal distribution
If np is greater than or equal to 5, and nq is greater than or equal to 5, estimate P(fewer than 8) with n =14 and p = 0.6 by using the normal distribution as an approximation to the binomial distribution; if np < 5 or nq < 5, then state that the normal approximation is ...
Wednesday, February 25, 2015 by slomomo

Statistics
What is the sample variance (not the population estimate) for: 1, 1, 2, 3, 5, 8.
Tuesday, February 24, 2015 by Alicia Estrada

Statistics
In a nominal data set, what is the preferred measure of central tendency?
Tuesday, February 24, 2015 by Luis

statistics
I know I posted this earlier but I found the answer I just don't know the steps to find it. Use technology to find the probability associated with the cumulative area to the left of the z score of the adjusted value of x, 5.5. P(z < - 0.5546) = 0.2896 If you could just ...
Tuesday, February 24, 2015 by Bradman0317

Statistics
A vending machine pours an average of 8.0 oz of coffee with a standard deviation of 0.2 oz if it is functioning properly. An inspector wants to take 16 cups of coffee from the machine to see if the machine is functioning well or not. He wants to have a significance level of 4...
Tuesday, February 24, 2015 by Daniel

statistics
use technology to find the probability associated with the cumulative area to the left of the z score of the adjusted value of x, 5.5 P(z< - 0.5546) = Im not sure if I need to look a z score table or how to redo this formula. I know the steps except for this. Please help.
Tuesday, February 24, 2015 by Bradman0317

Statistics and Probability
I took a large sample of households in a city, and based on that, estimate the standard deviation of the income for all households in the city is $800. In order to make a desired conclusion about the income for all the households in the city, I want the sample mean for another...
Tuesday, February 24, 2015 by Macy

Statistics
I took a large sample of households in a city, and based on that, estimate the standard deviation of the income for all households in the city is $800. In order to make a desired conclusion about the income for all the households in the city, I want the sample mean for another...
Tuesday, February 24, 2015 by Macy

statistics
If np is more or equal to 5 and nq is more or equal to 5, estimate P(fewer than 6) with n = 14 and p = 0.5 by using the normal distribution as an approximation to the binomial distribution; if np < 5 or nq < 5, then state that the normal approximation is not suitable. ...
Tuesday, February 24, 2015 by Bradman0317

statistics
A box contains 3 red marbles and 7 white marbles.A marble is drawn from the box,and a marble of the other color is then put into the box.A second marble is drawn from the box.Find the probability that the second marble is red.if both marbles were of same color.what is the ...
Tuesday, February 24, 2015 by collette

statistics
A comprehensive study of orphaned children is conducted in every orphanage in Australia. A scale called the Capacity for Attachment Scale is given to all orphaned children. The mean (μ) of the scale is 72 and the standard deviation (σ) is 13. Assuming that the scores...
Monday, February 23, 2015 by Alicia Estrada

statistics
If a fowl is treated, probability of dying is 1/10 while if not treated the probability is 7/10 calculate the probability that, a fowl picked at random from the 36 fowl is (i) Treated with the drug and will die (ii) Not treated with the drug and will die (iii) Not treated with...
Sunday, February 22, 2015 by kudu

statistics
The water supply in a town depends entirely on two pumps. A and B. The probability of pump A filling is 0.1 and the probability of pump B failing is 0.2. Calculate the probability that (a) Both pumps are working (b) There is no water in the town (c) Only one pump is working (d...
Sunday, February 22, 2015 by kudu

statistics
About 71% of dog owners buy holiday presents for their dogs. Suppose n = 4 dog owners are randomly selected. Find the expected number of persons, in the sample, who buy their dog holiday presents. Round to four decimal places.
Sunday, February 22, 2015 by m

statistics
A cell phone service provider has selected a random sample of 20 of its customers in an effort to estimate the mean number of minutes used per day. The results of the sample included a sample mean of 34.5 minutes and a sample standard deviation equal to 11.5 minutes. Based on ...
Sunday, February 22, 2015 by timothy kendricks

statistics
Consider the following situation, and answer each of the following multiple choice questions. In your write-up, just list the sub-question letter (A-J) and your answer – no need to restate the question or to justify your answer. Situation: You have 400 data points, which ...
Sunday, February 22, 2015 by marie

statistics
a hat contains 40 marbles, 16 of which are red and are green. if one marble is randomly selected out of this hat, what is the probability that this marble is red?
Sunday, February 22, 2015 by Anonymous

statistics
Factories A, B and C produce computers. Factory A produces 3 times as many computers as factory C, and factory B produces 6 times as many computers as factory C. The probability that a computer produced by factory A is defective is 0.02, the probability that a computer ...
Sunday, February 22, 2015 by cindy

statistics
A consumer advocacy group claims that the mean amount of juice in a 16 ounce bottled drink is not 16 ounces, as stated by the bottler.
Saturday, February 21, 2015 by Anonymous

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Homework Help: Math

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