Question

You are interested in finding a 95% 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 12 randomly selected college students.

3

12

8

1

10

10

6

1

7

7

4

9

a. To compute the confidence interval use a distribution.

b. With 95% confidence the population mean number of days of class that college students miss is between answer _____ and answer ________ days.

c. If many groups of 12 randomly selected non-residential college students are surveyed, then a different confidence interval would be produced from each group. About answer ______ percent of these confidence intervals will contain the true population mean number of missed class days and about answer ______ 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. With 95% confidence the population mean number of days of class that college students miss is between 4.2091 and 8.7909 days.

c. If many groups of 12 randomly selected non-residential college students are surveyed, then a different confidence interval would be produced from each group. About 95 percent of these confidence intervals will contain the true population mean number of missed class days and about 5 percent will not contain the true population mean number of missed class days.