A cell phone manufacturer inspects the video display on each color phone to verify that the screen can display all colors with the brilliance their customers have come to expect. Each phone is turned on, run through a self-test procedure, and classified as either acceptable or unacceptable based on test performance. Based on historical data, the process engineer expects about 0.1 percent defective displays. How many phones should they sample to establish an average fraction defective for their statistical quality control initiative?
A)5
B)50
C)500
D)5000

Question

Quizplus · Accepted Answer

To establish an average fraction defective for statistical quality control, especially when the expected defect rate is very low (0.1%), a large sample size is needed to accurately capture the defect rate. Sampling 5000 phones would provide a more reliable estimate of the true defect rate than smaller sample sizes, given the rarity of defects.

A Cell Phone Manufacturer Inspects the Video Display on Each