Question

You are the human resources director for a corporation and want to

implement a health improvement program for employees to decrease

employee medical absences. You perform a six-month study with a

random sample of employees. Your goal is to decrease absences by

50%. (Assume all data are normally distributed.)

 EXERCISES

1. Preliminary Thoughts

You got the idea for this health improvement program from a

national survey in which 75% of people who responded said they

would participate in such a program if offered by their employer.

You randomly select 60 employees and ask them whether they

would participate in such a program.

(a) Find the probability that exactly 35 will say yes.

(b) Find the probability that at least 40 will say yes.

(c) Find the probability that fewer than 20 will say yes.

(d) Based on the results in parts (a)–(c), explain why you chose to

perform the study.

2. Before the Program

Before the study, the mean number of absences during a six-month

period of the participants was 6, with a standard deviation of 1.5. An

employee is randomly selected.

(a) Find the probability that the employee’s number of absences is

less than 5.

(b) Find the probability that the employee’s number of absences is

between 5 and 7.

(c) Find the probability that the employee’s number of absences is

more than 7.

3. After the Program

The graph at the right represents the results of the study.

(a) What is the mean number of absences for employees? Explain

how you know.

(b) Based on the results, was the goal of decreasing absences by

50% reached?

(c) Describe how you would present your results to the board of

directors of the corporation.