View Answered Questions
No. & Date Asked  Question 

# 6 :: 10/23/07

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 
# 151 :: 4/14/08

A random sample of 25 households finds that an average of 2.3 people reside in each house (the standard deviation is 0.35). With a 95% confidence lev. . .
TINV,
tstatistic,
tdistribution,
Confidence Intervals,
Standard Error of the Mean,
Margin of Error 
# 197 :: 5/15/08

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 
# 212 :: 6/1/08

How would I figure out a 90% and 95% confidence interval for the below informaion? What would be the formula? Can I figure this out in Excel or Mega. . .
tdistribution,
Confidence Intervals,
TINV,
Margin of Error 
# 263 :: 7/6/08

Determine the critical value Za/2 that corresponds to 94% level of confidence
Compute the 90% confidence interval about m if the sample size, n, is. . .
Critical Value,
Confidence Intervals,
Margin of Error 
# 339 :: 8/12/08

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 
# 362 :: 9/1/08

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 
# 364 :: 9/4/08

A sample of 20 pages was taken without replacement from the 1,591page phone directory Ameritech Pages Plus Yellow Pages. On each page, the mean area . . .
Margin of Error,
Confidence Intervals,
Sample Size 
# 369 :: 9/5/08

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 
# 371 :: 9/8/08

Can you give me a formula to calculate sample size?. . .
Sample Size,
Margin of Error 
# 403 :: 9/22/08

Based on information obtained from a sample of 54, a 98% confidence interval for the average profit level of regional banks is given by 67.4 million t. . .
Standard Deviation,
Margin of Error,
Critical Value,
Confidence Intervals,
Confidence Level 
# 450 :: 10/3/08

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 
# 453 :: 10/4/08

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 
# 471 :: 10/9/08

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 
# 504 :: 11/9/08

Calculate the 95% confidence interval on the following GPA's from 30 randomly selected students.
0.979
0.891
0.962
0.858
0.909
0.936
0.963
0.9. . .
Confidence Intervals,
Margin of Error,
tstatistic 
# 505 :: 11/11/08

Calculate a 98% confidence interval for the following data 15.7,15.7,15.5,15.2,15.2,15.1,15.3.. . .
Confidence Intervals,
TINV,
Margin of Error,
tstatistic 
# 506 :: 11/12/08

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 
# 508 :: 11/13/08

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 
# 509 :: 11/13/08

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 
# 512 :: 11/14/08

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 
# 557 :: 12/16/08

Find the margin or error for the 95% confidence interval used to estimate the population proportion. In a survey of 7100 TV viewers, 38% said they wa. . .
Confidence Intervals,
Margin of Error 
# 632 :: 2/19/09

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 
# 685 :: 4/18/09

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 
# 858 :: 3/18/10

A questionnaire about study habits was given to a random sample of students taking a large introductory statistics class. The sample of 25 students re. . .
Margin of Error 
# 860 :: 3/30/10

Problem # 1:
Clothing for Runners: Your company sells exercise clothing and equipment on the internet. To design the clothing, you collect a data on. . .
Confidence Intervals,
Margin of Error 
# 868 :: 10/14/10

Suppose that a 90% confidence interval for a population mean μ is constructed from a sample, resulting in the interval from 120 to 150. What was. . .
Confidence Intervals,
Margin of Error 
# 893 :: 7/12/11

Elbow to fingertip length of men 99% confidence n=32, x 14.50,s= 0.70 what is the margin of error. . .
Margin of Error,
Confidence Intervals 