Homework Help: Math: Statistics

Recent Homework Questions About Statistics

statistics
The weather forecaster reports that the probability of rain tomorrow is 10%, Which approach was used to arrive at this number?
Monday, October 24, 2011 at 6:46pm

statistics
IQ scores are normally distributed and assume that the average IQ for all Economics majors is 108 with a standard deviation of 11. What percentage of Economics majors would have an IQ of more than 118?
Monday, October 24, 2011 at 2:28pm

statistics
Suppose the amount of time it takes for statistics students to complete their midterm is normally distributed with a mean of 85.70 minutes and a standard deviation of 22.55 minutes. If 10 students are randomly selected, what is the probability that they would average less than...
Monday, October 24, 2011 at 2:27pm

statistics
government data assign a single case or each death that occurs in the u.s. the data show that the probability is 0.45 that a randomly chosen death was due to cardiovascular disease, and 0.22 that i was due to cancer. Suppose a docote checked the cause of death of 2 randomly ...
Monday, October 24, 2011 at 2:12pm

statistics
The profit for a new product is given by Z = 2X - 2Y - 7. We know that X and Y are independent random variables with Var(X) = 2 and Var(Y) = 2.7. What is the variance of Z?
Monday, October 24, 2011 at 10:56am

Statistics
Consider a population with µ=73.6 and 0 = 5.38 (A) Calculate the z-score for x =72.7 from a sample of size 45. (B) Could this z-score be used in calculating probabilities using Table 3 in Appendix B of the text? Why or why not?
Monday, October 24, 2011 at 8:43am

STATISTICS
T-test independent that people can hear better after having eaten a large meal A researcher theorized that people can hear better when they have just eaten a large meal. Six individuals were randomly assigned to eat either a large meal or a small meal. After eating the meal, ...
Sunday, October 23, 2011 at 9:05pm

statistics
In a poll of voters in a certain city, 32% said that they backed a bill which would limit growth and development in their city. The margin of error was reported as 1.7% with 90% confidence. Determine the bounds for the confidence interval. A. (88.3%, 91.7%) B. (30%, 34%) C. (...
Sunday, October 23, 2011 at 8:12pm

Applied Statistics
Assignment Guidelines Perform a two-tailed hypothesis test using the steps outlined in the assignment description. In a Word document, create a report that includest the following: Null and alternate statements. Pasted Microsoft Excel data output. Identification of the ...
Sunday, October 23, 2011 at 6:05pm

Statistics
Suppose you know ó and you want an 85 percent confidence level. What value would you use to multiply the standard error of the mean by?
Sunday, October 23, 2011 at 5:14pm

statistics
Listed below are the FICO scores of a simple random sample of United States adults. Do these scores appear to come from a population that has a normal distribution? Explain how you arrived at your answer and defend your conclusion. 708 713 781 809 797 793 711 681 768 611 698 ...
Sunday, October 23, 2011 at 5:14pm

Stats
USA snapshot presented a bar graph depicting business travelers’ impression of wait times in airport security lines over the past 12 months. Statistics were derived from Travel Industry Association of American Business Traveler Survey of 2034 respondents. Is this a ...
Sunday, October 23, 2011 at 1:28pm

statistics
Seventy million pounds of trout are grown in the U.S. every year. Farm-raised trout contain an average of 32 grams of fat per pound, with a standard deviation of 7.5 grams of fat per pound. A random sample of 34 farm-raised trout is selected. The mean fat content for the ...
Sunday, October 23, 2011 at 8:46am

statistics
In a clinic, 62% of patients are female. Fifteen patients are selected at random with replacement. What is the probability that at least 1 of the fifteen patients is male?
Saturday, October 22, 2011 at 10:51pm

statistics
Given the following information about a sample, calculate a z score for a test grade of 91. = 87, s = 4.01
Saturday, October 22, 2011 at 9:59pm

Statistics
18. The Intelligence Quotient (IQ) test scores are normally distributed with a mean of 100 and a standard deviation of 15. Given a class with 25 students, what is the probability that the class' average IQ score is between 85 and 115? A) 0.0026 B) 0.4987 C) 3.00 D) 0.9974
Saturday, October 22, 2011 at 7:45pm

Statistics
28. A group of statistics students decided to conduct a survey at their university to find the average (mean) amount of time students spend studying per week. Based on a simple random sample, they surveyed 144 students. The statistics showed that students studied an average of...
Saturday, October 22, 2011 at 7:43pm

Math/Statistics
STATISTICS PLEASE HELP!!!!! I am sorry this is jy second time posting, but I really need help. I have tried contacting my teacher and classmates with no luck. Please just steer me in the right direction!: Suppose cars arrive at Burger King's drive-through at the rate of 20...
Saturday, October 22, 2011 at 6:21pm

Statistics
Suppose cars arrive at Burger King's drive-through at the rate of 20 cars every hour between 12:00 noon and 1:00 pm. A random sample of 40 one-hour periods between 12:00 noon and 1:00 pm is selected and has 22.1 as the sample mean number of cars arriving. (a) Why is the ...
Saturday, October 22, 2011 at 11:05am

Statistics
A retail shop accepts only cash or checks. Suppose that 54% of its customers carry cash, 51% carry checks, and 71% carry cash or checks (or both). What is the probability that a randomly chosen customer at the shop is carrying both cash and checks?
Saturday, October 22, 2011 at 9:54am

statistics
A company employs nine people and plans to select a group of six of these employees to receive advanced training. How many ways can the group of six employees be selected?
Friday, October 21, 2011 at 8:26pm

statistics, find the probability
It is known that 77% of all new products introduced in grocery stores fail (are taken off the market) within 2 years. If a grocery store chain introduces 62 new products, find the following probabilities. (Round your answers to four decimal places.) (d) within 2 years fewer ...
Friday, October 21, 2011 at 7:03pm

statistics
It is known that 77% of all new products introduced in grocery stores fail (are taken off the market) within 2 years. If a grocery store chain introduces 62 new products, find the following probabilities. (Round your answers to four decimal places.) (d) within 2 years fewer ...
Friday, October 21, 2011 at 3:06pm

statistics
A study of 40 psychology teachers showed that they spent, on average, 12.6 minutes correcting a student's final term paper. Find the 90 percent confidence interval of the mean time for all psychology teachers correcting final term papers when the deviation is 2.5.
Friday, October 21, 2011 at 2:55pm

statistics
A survey of college students was conducted during final exam week to assess the number of cups of coffee consumed each day. The mean number of cups was 5 with a standard deviation of 1.5 cups. The distribution was normal. a. What proportion of students drank 7 or more cups of ...
Thursday, October 20, 2011 at 2:23pm

statistics
Assuming that the data are normally distributed with a mean of 45 and a standard deviation of 3.25, what is the z-score for a value of 40?
Thursday, October 20, 2011 at 2:08pm

statistics
30 customers the first week and 55 customers the second week and 80 customers the third week, what would you project for week 4
Thursday, October 20, 2011 at 1:24pm

statistics
a batch of 25 used automobile alternators contains 3 defectives. if 3 alternators are sampled at random, find the probability of the event . (a). A=[none of the defectives appear ] (b). B=[exactly two defectives appear]
Thursday, October 20, 2011 at 12:29pm

Statistics
USA snapshot presented a bar graph depicting business travelers’ impression of wait times in airport security lines over the past 12 months. Statistics were derived from Travel Industry Association of American Business Traveler Survey of 2034 respondents. Is this a ...
Thursday, October 20, 2011 at 11:39am

statistics
perform a two tail hypothesis test on both the legal services satisfaction and the sentence satisfaction variable's data using a .05 significance level.
Thursday, October 20, 2011 at 9:31am

Statistics
Find the normal approximation for the binomial probability that x = 5, where n = 12 and p = 0.7. Compare this probability to the value of P(x=5) found in Table 2 of Appendix B in your textbook.
Thursday, October 20, 2011 at 7:50am

statistics
f(y)= (1/c)e^(-y/2) if y is greater than or equal to 0 and f(y)=(1/c)e^(y/2) if y is less than 0 a) What is c? b)What is the probability distribution function?
Wednesday, October 19, 2011 at 9:12pm

Statistics
Suppose we have a population of scores with a mean (ì) of 200 and a standard deviation (ó) of 10. Assume that the distribution is normal. Provide answers to the following questions: What score would cut off the top 5 percent of scores? What score would cut off ...
Wednesday, October 19, 2011 at 9:04pm

statistics
Assuming that the data are normally distributed with a mean of 45 and a standard deviation of 3.25, what is the z-score for a value of 40? (Points : 6) 1.54 2.38 -1.36 -1.54
Wednesday, October 19, 2011 at 8:35pm

statistics
Five percent of all items sold by 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, a) both will be returned for a refund b) neither will be returned for a refund
Wednesday, October 19, 2011 at 12:44am

statistics
There are 44 mathematics major and 163 computer science majors at the college. How many ways are there to pick 2 representatives, so that one is a mathematics major and the other is a computer science major?
Wednesday, October 19, 2011 at 12:01am

statistics
A company produces steel rods. The lengths of the steel rods are normally distributed with a mean of 121.2-cm and a standard deviation of 1.8-cm. Suppose a rod is chosen at random from all the rods produced by the company. There is a 23% probability that the rod is longer than...
Tuesday, October 18, 2011 at 11:45pm

statistics
With a µ = 100, a score of 150 is more extreme when ó = ______. a.25 b.100 c.both d.neither
Tuesday, October 18, 2011 at 10:19pm

statistics
microfracture knee surgery has a 75% chance of success on patients with degenerative knees. The surgery is performed on 5 patients. Find the probability of the surgery being successful on less than 3 patients
Tuesday, October 18, 2011 at 8:02pm

statistics
Using measures of center and measures of variability compare the number of hours on school work (Q11) and the number of hours watching television (Q14). a) Which variable has greater variability? How do you know? b) What number of hours on school work would be at the 10th ...
Tuesday, October 18, 2011 at 6:52pm

Statistics: IQ Score (X) and Exam Score (Y)
Assuming that the regression equation for the relationship between IQ score and psychology exam score is Y' = 9+ 0.274X, what would you expect the psychology exam scores to be for the following individuals given their IQ exam scores? Individual Tim Tom Tina Tory IQ Score (...
Tuesday, October 18, 2011 at 3:30pm

Statistics: Calculate a Pearson's r
In a study on caffeine and stress, college students indicated how many cups of coffee they drink per day and their stress level on a scale of 1 to 10. The data are provided in the following table. Number of Cups of Coffee 3, 2, 4, 6, 5, 1, 7, 3, 2, 4 Stress Level 5, 3, 3, 9, 4...
Tuesday, October 18, 2011 at 3:25pm

Statistics: Draw A Scatterplot
Draw a scatterplot indicating a strong negative relationship between the variables of income and mental illness. Be sure to label the axes correctly.
Tuesday, October 18, 2011 at 3:22pm

statistics
Considering that a researcher can test at the <p = .05 (95%), p = .01 (99%), or p = .001 (99.9%) level for statistical significance, how would you use these three levels in relationship to risk to patients in implementing the decisions of your research?
Tuesday, October 18, 2011 at 1:58pm

statistics
A manufacturer makes two models of an item: model A which accounts for 70% of unit sales, and model B which accounts for 30% of unit sales. Because of defects, the manufacturer has to replace (or exchange) 4% of its model A and 17% of its model B. Question 9 : If a unit is ...
Tuesday, October 18, 2011 at 10:57am

BUSINESS STATISTICS
The random variable x is normally distributed with mean =1,000 and standard deviation =100. Sketch and find each of the following probabilities: P(x<1,035)
Tuesday, October 18, 2011 at 6:20am

Statistics: Percentile Rank
A survey of college students was conducted during final exam week to assess the number of cups of coffee consumed each day. The mean number of cups was 5 with a standard deviation of 1.5 cups. The distribution was normal. A. What proportion of students drank 7 or more cups of ...
Tuesday, October 18, 2011 at 1:48am

Statistics: Range, Average Deviation, Standard Dev
Can someone please help me with the following math problems? I am totally lost and confused. Calculate the range, average deviation, and standard deviation for the following five distributions: A. 1, 2, 3, 4, 5, 6, 7, 8, 9 B. -4, -3, -2, -1, 0, 1, 2, 3, 4 C. 10, 20, 30, 40, 50...
Tuesday, October 18, 2011 at 1:44am

Statistics
Calculate the mean, median, and mode for the following data set. Is the distribution normal or skewed? If its skewed, is it positively skewed or negatively skewed? Which of these measures of central tendency would be most appropriate? Data Set: 100, 97, 99, 70, 72, 75, 82, 68...
Tuesday, October 18, 2011 at 1:41am

Math: Statistics
Organize the data into a class interval frequency distribution using 10 intervals with frequency (f) and relative frequency (rf). Data Set: 100, 97, 99, 70, 72, 75, 82, 68, 85, 88, 71, 77, 93, 94, 54, 59, 83, 87, 98, 84, 72, 96, 98, 89, 74, 98, 77, 82, 83, 98, 90, 95, 85, 76, ...
Tuesday, October 18, 2011 at 12:56am

statistics
A telephone company's goal is to have no more than four monthly line failures on any 50 miles of line. The company currently experiences an average of 4 monthly line failures per 25 miles of line. Let x denote the number of monthly line failures per 50 miles of line. ...
Monday, October 17, 2011 at 10:13pm

statistics
Smith is a weld inspector at a shipyard. He know from keeping track of good and substandard welds that for the afternoon shift 5% of all welds done will be at substandard. Smith checks 7500 shifts completed that shift and finds that 300 of them are substandard. Find the sample...
Monday, October 17, 2011 at 9:43pm

statistics
The Frayed Nerves Anxiety Scale (FNAS) is used to measure the anxiety level of people on a scale from 0 to 1000. Four students were randomly chosen and given the FNAS before their second exam. Their scores were 700, 653, 740, and 707. The standard deviation sigma of the test ...
Monday, October 17, 2011 at 7:10pm

statistics
From the MM207 Student Data Set identify the following: a) A variable measured at the nominal level of measurement. b) A variable measured at the ratio level of measurement. c) A variable measured at the ordinal level of measurement
Monday, October 17, 2011 at 6:56pm

statistics
given the data set below what would be the percentile rank of the number 6 2;8;6;9;5
Monday, October 17, 2011 at 5:02pm

statistics
what is a t-test
Monday, October 17, 2011 at 11:24am

Statistics
A set of 50 data values has a mean of 35 and a variance of 25. I. Find the standard score (z) for a data value = 26. II. Find the probability of a data value > 26.
Monday, October 17, 2011 at 7:29am

Statistics
SAT I scores around the nation tend to have a mean scale score around 500, a standard deviation of about 100 points, and are approximately normally distributed. What SAT I score within the population would have a percentile rank of approximately 16?
Monday, October 17, 2011 at 1:32am

Statistics
Scores on the Stanford-Binet Intelligence scale have a mean of 100 and a standard deviation of 16, and are presumed to be normally distributed. A person who scores 68 on this scale has what percentile rank within the population?
Monday, October 17, 2011 at 1:31am

Statistics
A sample of purchases at the local convenience store has resulted in the following sample data, where x = the number of items purchased per customer and f = the number of customers. x 1 2 3 4 5 f 5 15 8 8 7 •What does the 15 stand for in the above table? •Find the ...
Monday, October 17, 2011 at 1:30am

Statistics
In each of the four examples listed below, one of the given variables is independent (x) and one of the given variables is dependent (y). Indicate in each case which variable is independent and which variable is dependent. I. Rainfall; Crop yield II. Taxi fare; Length of ride ...
Monday, October 17, 2011 at 1:29am

Statistics
A student scored 81 percent on a test, and was in the 77th percentile. Explain these two numbers.
Monday, October 17, 2011 at 1:28am

Statistics
In terms of the mean and standard deviation: -What does it mean to say that a particular value of x has a standard score of +2.1? -What does it mean to say that a particular value of x has a z-score of -2.4?
Monday, October 17, 2011 at 1:28am

Statistics
The following data lists the average monthly snowfall for January in 15 cities around the US: 29 26 6 46 17 34 15 45 19 43 37 6 9 33 37 Find the mean, variance, and standard deviation.
Monday, October 17, 2011 at 12:20am

Statistics
Starting with the data values 70 and 100, add three data values to the sample so that the mean is 81, the median is 91, and the mode is 91. How do i do this??
Sunday, October 16, 2011 at 10:29pm

statistics
a.a statistics practitioner randomly sampled 100 observations from a population with a standard deviation of 5 and found that x is 10. Estimate the population mean with 90% confidence. Repeat (a) with a sample sixe of 25
Sunday, October 16, 2011 at 9:12pm

statistics
{Exercise 3.55} Morningstar tracks the total return for a large number of mutual funds. The following table shows the total return and the number of funds for four categories of mutual funds (Morningstar Funds500, 2008). a. Using the number of funds as weights, compute the ...
Sunday, October 16, 2011 at 8:35pm

statistics
the coach wants to introduce each of the starting players at tuesday's game. in how many different orders can each of the 5 starting players be introduced?
Sunday, October 16, 2011 at 11:10am

statistics
A study of graduates average grades and degrees showed the following results: B.S. Degrees, 15 graduates averaged Grade A, 8 graduates averaged Grade B, and 5 graduates averaged grade C. Graduates who had a B.A. Degree, 8 averaged grade A, 12 averaged grade B, and 7 averaged ...
Saturday, October 15, 2011 at 8:05pm

statistics
draw a distribution curve that represents the following distribution of scores: results of 6th grade math test given to college students
Saturday, October 15, 2011 at 7:39pm

statistics
Starting with a population that is normally distributed with a mean of 100 and a standard deviation of 12, answer the following questions (if possible). a. What is the probability of randomly drawing a single score between 100 and 106, p(100 < X < 106)? b. What is the ...
Saturday, October 15, 2011 at 4:04pm

statistics
a die is rolled 7 times. find the probability of getting at least one 3.
Saturday, October 15, 2011 at 12:51am

statistics
You ask a neighbor to water a sickly plant while you are on vacation. Without water the plant will die with probability 0.7. With water it will die with probability 0.6. You are 84 % certain the neighbor will remember to water the plant. You come back from the vacation and the...
Friday, October 14, 2011 at 1:06pm

statistics math &146
Outstanding balance on each account. is it a mean median or mode
Friday, October 14, 2011 at 1:58am

Statistics
in a typical year, about 46,000 deaths result from car accidents. How manyu deaths would result from car accidents in a typical 4 day period?
Thursday, October 13, 2011 at 11:53pm

statistics
What is the standard deviation of a normal distribution, whose mean is 35, in which an x-value of 23 has a z-score of -1.63?
Thursday, October 13, 2011 at 5:02pm

Statistics
An auditor wants to estimate what proportion of a bank’s commercial loan files are incomplete. The auditor wants to be within 10% of the true proportion when using a 95% confidence level. How many files must the auditor sample? No estimate of the proportion is available, ...
Thursday, October 13, 2011 at 1:50pm

Statistics
A private medical clinic wants to estimate the true mean annual income of its patients. The clinic needs to be within $500 of the true mean. The clinic estimates that the true population standard deviation is around $2,300. If the confidence level is 95%, find the required ...
Thursday, October 13, 2011 at 1:49pm

statistics
If the city spends $145000 on promotional expenditures, what will be the projected attendance @ 95% confidence level?
Thursday, October 13, 2011 at 9:31am

Statistics
Suppose we want to determine the (binomial) probability (p) of getting 4 heads in 15 flips of a 2-sided coin. Using the Binomial Probabilities Table in Appendix B of the text, what values of n, x and p would we use to look up this probability, and what would be the probability?
Thursday, October 13, 2011 at 8:43am

statistics
A telemarketing supervisor tells a new worker that the odds of making a sale on a single call are 4 to 15. What is the probability of a successful call? (Enter your answer to 2 decimal places.)
Thursday, October 13, 2011 at 2:56am

statistics
he owners of a two-person business make their decisions independently of each other and then compare their decisions. If they agree, the decision is made; if they do not agree, then further consideration is necessary before a decision is reached. Each has a history of making ...
Wednesday, October 12, 2011 at 11:51pm

Statistics
In an exam, we randomly chose some students who get both the pretest and the posttest. We are interested in the difference of the score of two test. Assume that the ¦Ò of score difference is 10 and the difference follows a normal distribution. If the H0 ...
Wednesday, October 12, 2011 at 10:30pm

Statistics
The production process of computer parts uses two machines one old & one new. If the old machine is used the probability that the defected part is produced is .13 if the new machine is used the probability that the defective part is produced is .04. moreover, the new machine ...
Wednesday, October 12, 2011 at 9:54pm

Statistics
Start with x = 100 and add four x values to make a sample of five data such that the standard deviation of these data equals 0
Wednesday, October 12, 2011 at 4:44pm

Statistics
A set of 50 data values has a mean of 15 and a variance of 25. Find the standard score of a data value = 20
Wednesday, October 12, 2011 at 4:44pm

Statistics
Using the 68-95-99.7 Rule. Find the percentage of ACT score within 9.6 of the mean of 21.1?
Wednesday, October 12, 2011 at 2:38pm

statistics
Using the data set below please calculate the 2;8;6;9;5 Range What would be the percentile rank of the number 6? Help please!
Wednesday, October 12, 2011 at 2:24pm

statistics
mean wage of 5 employee is Rs.1000 of the wages of 4 emoloyee are Rs 800 rs 1200 rs 1300 rs 900.find the wages of 5th employee?
Wednesday, October 12, 2011 at 12:52pm

Statistics
The mean graduation time is 5 years with a standard deviation of 6 months for the Monte Carlo College, in which the graduation time is related to the grade of the students. The class size is normally 40. Calculate how many students may graduate by the end of the fourth year. ...
Wednesday, October 12, 2011 at 5:39am

Statistics
How would you interpret the findings of a correlation study that reported a linear correlation coefficient of − 1.34?
Tuesday, October 11, 2011 at 8:21pm

Engineering Statistics
"A study has shown that 20% of all college textbooks have a price of $90 or higher. It is known that the standard deviation of the prices of all college textbooks is $9.50. Suppose the prices of all college textbooks have a normal distribution. What is the mean price of ...
Tuesday, October 11, 2011 at 3:13pm

statistics
A sample of 12 measurements has a mean of 20 and a standard deviation of 2. Suppose that the sample is enlarged to 14 measurements, by including two additional measurements having a common value of 20 each. Find the standard deviation of the sample of 14 measurements.
Tuesday, October 11, 2011 at 2:28pm

statistics
construct the confidence interval for the population mean c=0.98,x=5.6, s=0.6, and n=45
Tuesday, October 11, 2011 at 12:53pm

STATISTICS 014
1. A manager wishes to find out whether there is a relationship between the age of his employees and the number of sick days they take each year. The data is given below: Age (X) 18 26 39 48 53 58 24 50 Days (Y) 16 12 9 5 6 2 10 7 a. What is the null hypothesis? b. What is the...
Tuesday, October 11, 2011 at 9:32am

statistics
A city survey found that 47% of teenagers have a part time job. The same survey found that 78% plan to attend college. If a teenager is chosen at random, what is the probability that the teenager has a part time job and plans to attend college?
Tuesday, October 11, 2011 at 1:31am

Statistics
An investment broker reports that yearly returns on common stocks are normally distributed with a mean of 12.4 percent and a standard deviation of 20.6 percent. (Round all k amounts to three decimal places. A negative sign should be used instead of the parentheses. For Z, use ...
Monday, October 10, 2011 at 9:54pm

Statistics
The daily water consumption for an Ohio community is normally distributed with a mean consumption of 750,000 gallons and a standard deviation of 80,000 gallons. The community water system will experience a noticeable drop in water pressure when the daily water consumption ...
Monday, October 10, 2011 at 9:52pm

Statistics
In a murder trial in Los Angeles, a shoe expert stated that the range of heights of men with a size 12 shoe is 72 inches to 76 inches. Suppose the heights of all men wearing size 12 shoes are normally distributed with a mean of 73.5 inches and a standard deviation of 1 inch. ...
Monday, October 10, 2011 at 9:51pm

elementary statistics
at a particular school with 200 male students, 58 play football 40 plays basketball and 8 plays both. what is the probablity that a randomly selected male student plays neither
Monday, October 10, 2011 at 11:10am

Government US
26. U.S. Bureau of Labor statistics reveal that the great majority of those workers who lost their jobs in 2001 did so because a. they are lazy. b. of either a temporary layoff or the permanent elimination of a job position. c. they were undereducated for the work they were ...
Monday, October 10, 2011 at 8:16am

statistics
You plan to conduct a survey to find what proportion of the workforce has two or more jobs. You decide on the 90 percent confidence level and state that the estimated proportion must be within 2 percent of the population proportion. A pilot survey reveals that 7 of the 50 ...
Sunday, October 9, 2011 at 9:49pm

Statistics
A forest fire is burning down a narrow valley 3 miles wide at a speed of 40 feet per minute. The fire can be contained by cutting a firebreak through the forest across the valley. It takes 30 seconds for one person to clear one foot of the firebreak. The value of lost timber ...
Sunday, October 9, 2011 at 9:04pm

statistics
Forty percent of participants in a soccer league are nine years old, 30% are eight, 20% are seven, and 10% are six. What is the expected value of the age and the standard deviation?
Sunday, October 9, 2011 at 8:35pm

Statistics
For the overall population, the IQ scores follow the normal distribution with mean equal to 100 and variance equal to 225. What is the best answer? A. If you pick a person at random, the chance that his IQ falls between 100 to 115 is more than the chance that his IQ falls ...
Sunday, October 9, 2011 at 4:47pm

Statistics
A random sample of dates taken from headstones at a cemetery in Pleasanton, California, showed an average lifespan of 70 years with a standard deviation of 20 years. Assuming the distribution is unimodal, which of the following is most likely a good description of the ...
Sunday, October 9, 2011 at 4:45pm

Stats
A random sample of dates taken from headstones at a cemetery in Pleasanton, California, showed an average lifespan of 70 years with a standard deviation of 20 years. Assuming the distribution is unimodal, which of the following is most likely a good description of the ...
Sunday, October 9, 2011 at 4:44pm

Statistics
7. Give and interpret the 95% confidence interval for the hours of sleep a student gets.
Sunday, October 9, 2011 at 3:53pm

statistics
The deli special lunch offers a choice of three different sandwiches, four kinds of salads, and five different desserts. Use the multiplication rule of counting to determine the number of different lunches that can be ordered using the deli special lunch option, if each ...
Sunday, October 9, 2011 at 3:42pm

Statistics
Calculate the mean and standard deviation of the probability distribution created by rolling a dice. Either show work or explain how your answer was calculated.
Sunday, October 9, 2011 at 1:33pm

statistics
Suppose that contamination particle size in micrometers can be modeled as f(x) = 2x−3 for 1 < x. a. Show that f(x) is a probability density function. b. Find the mean X.
Sunday, October 9, 2011 at 1:20pm

statistics
is the mean or median a better estimate for the parameter of interest?
Sunday, October 9, 2011 at 1:23am

statistics
Can any help me how to solve below problem.? I am student and learning OC curve and double sampling plan. Can you someone help me how to understand this concept? A shipment of 1000 items is to be inspected on a sampling basis. The producer and the consumer have agreed to adopt...
Sunday, October 9, 2011 at 1:17am

Statistics
Each year, thousands of college seniors take the Graduate Record Examination (GRE). Assume the scores are transformed so they have a mean of 600 and a standard deviation of 150. Furthermore, the scores are known to be normally distributed. Determine the percentage of students ...
Saturday, October 8, 2011 at 11:43pm

Statistics
Given IQ~N(100, 256) find P(IQ > 115). Be certain to set your calculator to FLOAT 4 to match my answer exactly. I need to know how to figure this out on my calculator.... no one has taught me how to use my calc and I am so confused.... someone please help!
Saturday, October 8, 2011 at 9:06pm

Statistics-confused
A candidate for a political office claims that he will win the election. A poll is conducted, and 35 of 150 voters indicate that they will vote for the candidate, 100 voters indicate that they will vote for his opponent, and 15 voters are undecided. a. What is the population ...
Saturday, October 8, 2011 at 5:02pm

College biology
In testing synaptic transmission, you found that there were 300 failures in 1000 trails of stimulating a presynaptic neuron. The average EPSP size was .7 mV +/- .2mV (mean +/- SD), and the average 'mini' EPSP size was .6mV +/- .1mV. Does the synapse obey Poisson ...
Saturday, October 8, 2011 at 2:44pm

Statistics
Classify the following variable as nominal, ordinal, discrete, or continuous and state why it is such a variable: number of US Senators
Saturday, October 8, 2011 at 1:50pm

Statistics
Describe whether the following study would most likely be “observational” or “experimental”, and why it would be so. * Mystery shoppers monitor the preferences at a shopping mall
Saturday, October 8, 2011 at 1:49pm

Statistics and Probability
In a game of skill, a player has probability 1/3,5/12,1/4 of scoring 0,1,2 respectively and the game ends when he scores a zero. Assuming independence of trials, find the probability of the total score being 'n' when the game ends?
Friday, October 7, 2011 at 11:18pm

Statistics
People were polled on how many books they read the previous year. How many subjects are needed to estimate the number of books read the previous year within one book with 90% confidence? Initial survey results indicate that standard deviation= 15.5 books.
Friday, October 7, 2011 at 10:18pm

statistics
The sum of the draws from a box is 440. If the average of these draws is 2.20, how many draws were there?
Friday, October 7, 2011 at 9:26pm

statistics
What SPECIFIC statistical test would be applied to these data collected to answer the following questions? What’s the average amount of pain Mr. Smith reported yesterday? Is there a significant difference in depression levels (using a scale of 0-60) between pts who take ...
Friday, October 7, 2011 at 4:09pm

Statistics
I have provided information from #3-5 in order to answer #6.. 3. Give the mean for the mean column of the Worksheet. Is this estimate centered about the parameter of interest (the parameter of interest is the answer for the mean in question 2)? The Mean for Column “mean&#...
Friday, October 7, 2011 at 12:00pm

statistics
To test H0:µ =80 versus H1:µ < 80, a simple random sample of size n = 22 is obtained from the population that is known to be normally distributed. (a) If = 76.9 and s = 8.5, compute the test statistic. (b) If the researcher decides to test the hypothesis at the...
Friday, October 7, 2011 at 9:19am

statistics
SAT Exam Scores – A school administrator wonders if students whose first language is not English score differently on the math portion of the SAT exam than students whose first language is English. The mean SAT math score of students whose first language is English is 516...
Friday, October 7, 2011 at 9:18am

Statistics
Four people(North, South, East, West) are each dealt 13 cards from an ordinary deck of 52 cards. a. If South has exactly one ace, what is the probability that his partner North has the other three aces? b. If North and South together have 10 hearts, what is the probability ...
Friday, October 7, 2011 at 3:01am

Statistics
A student science club consists of 20 biology majors, 13 chemistry majors, and 8 physics majors. One student from each of the three sciences is to be selected to participate in a special project. How many different ways can these three students be selected?How many ways can ...
Thursday, October 6, 2011 at 5:13pm

HELP ASAP ( COLLEGE STATISTICS)
Describe in words the nature of the relationship between each pair of variables as indicated by the value of the correlation coefficient. Be sure to include a. the direction of the relationship. b. the strength of the relationship. c. a verbal description of the way the ...
Thursday, October 6, 2011 at 4:51pm

statistics
A 90% confidence interval for a population mean based on 144 observations is computed to be (2.7,3.4). How many observations must be made so that 90% confidence interval will specify the mean to within ± 0.2
Thursday, October 6, 2011 at 2:08pm

statistics
There are eight balls in an urn. They are identical except for color. Five are red, two are blue, and one is yellow
Thursday, October 6, 2011 at 11:41am

Statistics
Starting with the data values 70 and 100, add three data values to the sample so that the mean is 81, the median is 94, and the mode is 94. Please show all of your work.
Thursday, October 6, 2011 at 6:44am

Analytical Skills
If your score on a statistics exam was 76 and the professor gave you the distribution for the exam score for your class, you could find your percentile to understand where you stand in comparison to your fellow students. Assume that the distribution for exam scores is normally...
Thursday, October 6, 2011 at 6:28am

statistics
6. A geography student needs to take three 300- level and three 400- level geography classes next semester in order to graduate. If there are 10 300- level courses being offered and 7 400- level courses being offered, how many different schedules could the student have?
Thursday, October 6, 2011 at 1:07am

statistics
A random sample of state gasoline taxes in cents is shown here for 12 states. Use the data to estimate the true population mean gasoline tax with 90% confidence. Does you interval contain the national average of 44.7 cents? 38.4 40.9 67 32.5 51.5 43.4 38 43.4 50.7 35.4 39.3 41.4
Wednesday, October 5, 2011 at 11:15pm

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. 95% confidence intervals: 6.214, 7.686 99% confidence intervals: 5.944, 7.956
Wednesday, October 5, 2011 at 3:54pm

Math(Statistics)
A certain soccer team wins (W) with P(W)= 60%, loses(L) with P(L) = 30%, and ties (T) with P(T) = 10%. The team plays three games over the weekend. a.Determine the elements of the event A that the team wins at least twice and does not lose. b.Find P(A) c.Determine the elements...
Wednesday, October 5, 2011 at 10:48am

MATH(Statistics)
Students are given three chances to pass a basic skills exam for permission to enrol in Calculus. Sixty percent of the students pass on the first try, of those that fail on the first try, fifty four percent pass on the second try, and of those remaining, forty eight percent ...
Wednesday, October 5, 2011 at 10:40am

statistics
what is the inter quartile range of a set of numbers adding to to 76
Wednesday, October 5, 2011 at 10:39am

MATH(STATISTICS)
Urn A contains R red balls and W white balls, urn B contains r red balls and w white balls. a.If an urn is selected at random and a ball drawn, what is the probability that the ball is red? b.If a ball is drawn from urn A and put into urn B, and then a ball is drawn from urn B...
Wednesday, October 5, 2011 at 10:33am

STATISTICS
Four people(North, South, East, West) are each dealt 13 cards from an ordinary deck of 52 cards. a. If South has exactly one ace, what is the probability that his partner North has the other three aces? b. If North and South together have 10 hearts, what is the probability ...
Wednesday, October 5, 2011 at 10:26am

Pages: <<Prev | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | Next>>

Post a New Question | Current Questions

Homework Help: Math

For Further Reading