A testing engineer in a light bulb factory is planning a study to estimate the average life of a large shipment of light bulbs.The engineer wants to estimate the average life within plus or minus 16 hours with 95 percent confidence.Assuming a process standard deviation of 90 hours,determine the sample size for this study.
A)7
B)43
C)58
D)122

Question

Quizplus · Accepted Answer

The sample size can be calculated using the formula for the sample size of a mean: n = (Z*σ/E)^2, where Z is the Z-score for 95% confidence (1.96), σ is the standard deviation (90), and E is the margin of error (16). Plugging in these values gives n ≈ 122.

A Testing Engineer in a Light Bulb Factory Is Planning