Question

You are interested in finding a 98% confidence interval for the average number of days of class that college students miss each year. The data below show the number of missed days for 11 randomly selected college students. Round answers to 3 decimal places where possible.

6 8 3 4 0 4 6 8 11 6 12

a. To compute the confidence interval use a _____distribution.

b. With 98% confidence the population mean number of days of class that college students miss is between _____and ______days.

c. If many groups of 11 randomly selected non-residential college students are surveyed, then a different confidence interval would be produced from each group. About _____percent of these confidence intervals will contain the true population mean number of missed class days and about _____percent will not contain the true population mean number of missed class days.

Answer 1

a. To compute the confidence interval use a  t  distribution.

b.

So, With 98% confidence the population mean number of days of class that college students miss is between 3.275 and 9.089 days.

c. If many groups of 11 randomly selected non-residential college students are surveyed, then a different confidence interval would be produced from each group. About 98 percent of these confidence intervals will contain the true population mean number of missed class days and about 2 percent will not contain the true population mean number of missed class days.