Question

A quality engineer selects an SRS of 100 switches from a large shipment for detailed inspection. Unknown to the engineer, usually 10% of the switches in the shipment fail to meet the specifications.

What is the probability that at most 9 switches fail the standard test in the sample?

Answer 1

Solution :

Given that,

Using binomial distribution,

= n * p = 100 * 0.10 = 10

= n * p * q = 100 * 0.10 * 0.90 = 3

Using continuity correction ,

= P((x - ) / (9.5 - 10) / 3)

= P(z 0.17)

Probability = 0.4325