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 population standard deviation.

Interpret the results.

Data from Exercises 3

The data set represents the amounts of time (in minutes) spent checking email for a random sample of employees at a company.

7.5 2.0 12.1 8.8 9.4 7.3 1.9 2.8 7.0 7.3