Chapter 21, Problem 4AT

You have just been hired as the quality control manager for Pressure Point Manufacturing, a company producing fuel injection systems for General Motors, Fold, and Chrysler. Top management has requested a status report on the number of defective units produced each day. You decide to keep track of the number of defects each day for 30 days. Following are the results of your survey.

Pressure Point Manufacturing—Defects per Jay—Survey I

11	13	17	13	15	9	14	11	13	15	11	10	14	12	15
19	15	13	17	9	20	13	14	18	16	15	14	17	18	13

a. Find the mean. median, mode, and range of these data for your report to top management.

After implementing your suggestions for improved quality on the production line, you decide to survey the defects for another 30 days with the following results:

Pressure Point Manufacturing—Defects per Jay—Survey 2

11	9	12	7	8	10	12	8	9	10	9	7	11	12	8
7	9	11	8	6	12	10	8	8	7	9	6	10	9	11

b. Find the mean. median, mode, and range of the new data.

c. If the company’s cost to fix each defective unit is $75, use the mean of each survey to calculate the average cost per day for defects before and after your improvements.

d. Theoretically, how much will your improvements save the company in a 300-day production year?

e. Congratulations! The company has awarded you a bonus amounting to $15\%$ of the first year's savings. How much is your bonus check?