Statistical Quality Control: Star Ferry Products, Ltd. manufactures a line of microcomputer motherboards. The company manufactures these boards in two divisions: Hong Kong Division and Kowloon Division. Company specifications indicate that each board should cost $460 and that for a day's production of boards at each division, the standard deviation for the average cost is $36. Exhibit B shows the average unit cost for production for the first 17 days of the month.

The company uses a three-standard deviation control limit for variance investigation purposes.

Required:

a. Which variances would you investigate? Why?

b. Prepare a statistical quality control chart for each of the two divisions.

Transcribed Image Text:

Exhibit B (25-33) Day Hong Kong Division Unit Cost Kowloon Division Unit Cost 10 11 12 13 14 15 16 17 -234567890-234567 $445 $485 469 471 427 427 439 439 421 445 429 321 449 449 455 455 461 433 448 571 452 4521 466 446 475 459 468 468 473 473 520 501 555