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No. & Date AskedQuestion
# 945 :: 4/29/12
Question 945 has been Answered
In a survey of 1000 electors, 20% were found to favour party "stats". 1. Construct a 95% C.I for the percentagew in favour of party "stats". 2. What. . .

Confidence Intervals, Sample Size

# 869 :: 10/14/10
Question 869 has been Answered
You need to estimate the mean Christmas sales across a large chain of jewelry stores. You want to estimate this mean value to within $100 with 99% co. . .

Sample Size

# 836 :: 1/13/10
Question 836 has been Answered
a statistician was setting up a hypothesis test with a level of significance dictated by upper management. However, she was concerned that the test wo. . .

Type II Error, Sample Size

# 821 :: 10/18/09
Question 821 has been Answered
A manufacturer can typically process 176-264 devices a given period of concern. In this situation the processing event is either pass or fail. There i. . .

Power, Sample Size, Effect Size, 1-Proportion Test

# 781 :: 7/14/09
Question 781 has been Answered
I am to do a study that involves people whose IQ are in the normal range 70 to 130. How many people must I screen with IQ test in order to find a samp. . .

Sample Size

# 720 :: 5/5/09
Question 720 has been Answered
City Opera, a local opera company, wishes to take a sample of its subscribers to learn the average number of years people have been subscribing. The d. . .

Sample Size

# 685 :: 4/18/09
Question 685 has been Answered
NKU needs to estimate the mean number of hours that all students work to earn money, on average, per week during the full semesters (fall and spring).. . .

Sample Size, Margin of Error

# 632 :: 2/19/09
Question 632 has been Answered
An automobile manufacturer wants to estimate the mean gasoline mileage that its customers will obtain with its new compact model. How many sample runs. . .

Sample Size, Margin of Error

# 551 :: 12/12/08
Question 551 has been Answered
Philadelphia is conducting a study on the characteristics of tourists who drive to Eagles football games. Previous studies indicate that approximately. . .

Sample Size, Confidence Intervals, Proportion

# 512 :: 11/14/08
Question 512 has been Answered
When estimating the mean of a population, how large must the sample be in order that the 95% error margin is 1/8 the standard deviation?. . .

Sample Size, Margin of Error, Standard Deviation, Standard Error of the Mean

# 510 :: 11/13/08
Question 510 has been Answered
Survey to determine what proportion of new car buyers continue to have their car serviced at the dealership after warranty ends. Estimates 30% of cust. . .

Sample Size, Confidence Level

# 509 :: 11/13/08
Question 509 has been Answered
A researcher expects the population proportion of the Cubs Fans in Chicago to be 80%. Error of less than 5% confident of an estimate to be made from a. . .

Confidence Intervals, Sample Size, Margin of Error

# 508 :: 11/13/08
Question 508 has been Answered
In a national wide survey a researcher expects 30 percent of the population will agree with an value statement. He wishes to have less than 2% error a. . .

Sample Size, Margin of Error, Confidence Level

# 507 :: 11/12/08
Question 507 has been Answered
In a survey of 500, 60% responded positively to an value question. Calculate a confidence level at 95% to get an interval estimate for proportion?. . .

Sample Size, Confidence Intervals, Proportion

# 506 :: 11/12/08
Question 506 has been Answered
Suppose you are planning a sample of employees to determine the monthly average # of vacation days. Standards set: Confidence level of 99% and an erro. . .

Sample Size, Margin of Error, Confidence Intervals

# 495 :: 11/4/08
The EPA range for a car is 20-28mpg, how large of a sample would be required to estimate your mean mpg with an error of +/- 1 mpg with 90% confidence. . .

Sample Size

# 471 :: 10/9/08
Question 471 has been Answered
A central university has a student population of 60,000. The university is interested in determining what proportion of them is in favour of a new gra. . .

Margin of Error, Confidence Intervals, Sample Size

# 453 :: 10/4/08
Question 453 has been Answered
A central university has a student population of 60,000. The university is interested in determining what proportion of them is in favour of a new gra. . .

Sample Size, Margin of Error

# 450 :: 10/3/08
Question 450 has been Answered
A researcher is interested in estimating the average salary of fire fighters in a large city. He wants to be 95% confident that his estimate is correc. . .

Margin of Error, Sample Size

# 371 :: 9/8/08
Question 371 has been Answered
Can you give me a formula to calculate sample size?. . .

Sample Size, Margin of Error

# 369 :: 9/5/08
Question 369 has been Answered
A random sample of 10 miniature Tootsie Rolls was taken from a bag. Each piece was weighed on very accurate scale. The results in grams were 3.087 3.. . .

Margin of Error, Sample Size, Confidence Intervals

# 364 :: 9/4/08
Question 364 has been Answered
A sample of 20 pages was taken without replacement from the 1,591-page phone directory Ameritech Pages Plus Yellow Pages. On each page, the mean area . . .

Margin of Error, Confidence Intervals, Sample Size

# 362 :: 9/1/08
Question 362 has been Answered
Popcorn kernels take between 100 and 200 seconds to pop. What sample size (number of kernels) would be needed to estimate the true mean seconds to pop. . .

Small Sample, Sample Size, Margin of Error, Confidence Intervals

# 339 :: 8/12/08
Question 339 has been Answered
My question is really about sample size. Say you work at a facility and want to perform an assessment of your safety culture – this would involve mul. . .

Sample Size, Margin of Error

# 214 :: 6/2/08
Question 214 has been Answered
I am charged with sampling expense report submissions for accuracy. We get 8000 T&E claims, and want to sample a subset making inferences about the p. . .

1-sample t-test, Confidence Intervals, Sample Size

# 211 :: 5/29/08
Question 211 has been Answered
State the main points of the Central Limit Theorem for a mean. B. Why is population shape of concern when estimating a mean? What does sample size hav. . .

Central Limit Theorem, Sample Size

# 203 :: 5/22/08
Question 203 has been Answered
How to determine the sample size for comparing mulltiple parameters like Height , weight, Blood pressure , Blood parameters like blood glucose, total. . .

Sample Size, Power, ANOVA, t-test

# 197 :: 5/15/08
Question 197 has been Answered
Annual starting salaries for college graduates with degrees in business administration are generally expected to be between $30,000 and $45,000. Assum. . .

Normally Distributed, Standard Deviation, Margin of Error, Sample Size

# 6 :: 10/23/07
Question 6 has been Answered
How do you determine the sample size for data for which the mean and standard deviation are not known?. . .

Standard Deviation, Sample Size, Margin of Error