Questions from Statistics

Q: In a survey of 1018 U.S. adults, 753

In a survey of 1018 U.S. adults, 753 say that the energy situation in the United States is very or fairly serious. a. Find the point estimate for the population proportion. b. Construct a 90% confid...

Q: Refer to the data set in Exercise 3. Assume the population

Refer to the data set in Exercise 3. Assume the population of times spent checking email is normally distributed. Construct a 95% confidence interval for a. the population variance and b. the popula...

Q: The winning times (in hours) for a sample of 30

The winning times (in hours) for a sample of 30 randomly selected Boston Marathon Women’s Open Division champions are shown in the table at the left. a. Find the point estimate of the population mean...

Q: You wish to estimate the mean winning time for Boston Marathon Women’s

You wish to estimate the mean winning time for Boston Marathon Women’s Open Division champions. The estimate must be within 0.13 hour of the population mean. Determine the minimum sample size required...

Q: Use the confidence interval to find the margin of error and the

Use the confidence interval to find the margin of error and the sample mean. (7.428, 7.562)

Q: Find the indicated binomial probabilities. If convenient, use technology or

Find the indicated binomial probabilities. If convenient, use technology or Table 2 in Appendix B. Thirty-nine percent of U.S. adults have a gun in their home. You randomly select 12 U.S. adults. Find...

Q: Determine the minimum sample size required to be 95% confident that

Determine the minimum sample size required to be 95% confident that the sample mean waking time is within 10 minutes of the population mean waking time. Use the population standard deviation from Exer...

Q: Determine the minimum sample size required to be 99% confident that

Determine the minimum sample size required to be 99% confident that the sample mean driving distance to work is within 2 miles of the population mean driving distance to work. Use the population stand...

Q: Find the critical value tc for the level of confidence c and

Find the critical value tc for the level of confidence c and sample size n. c = 0.80, n = 10

Q: Find the critical value tc for the level of confidence c and

Find the critical value tc for the level of confidence c and sample size n. c = 0.95, n = 24