Maher, Barney, and White LLC is a legal firm with 40 employees. All of the firm’s employees are eligible to participate in the company’s 401(k) plan, and the firm is proud of its 100% participation rate.

The file MBW 401 contains last year’s year-end 401(k) account balance for each of the firm’s 40 employees.

a. Compute the population mean and population standard deviation for the year-end 401(k) account balances at Maher, Barney, and White.

b. Suppose that an audit of the firm’s 401(k) plan is being conducted and 12 randomly selected employee account balances are to be examined. If the following employees (indicated by employee number) are randomly selected to be included in the study, what is the estimate for the year-end mean 401(k) account balance? How much sampling error is present in this estimate?

Employee #
26 8 31 3 38 30 17 9 21 39 18 11

c. Calculate the range of possible sampling error if a random sample of 15 employees is used to estimate the year-end mean 401(k) account balance.