Question

A batch of 140 semiconductor chips is inspected by choosing a sample of 5 chips. assume that 10 of the chips do not conform to customer requirements. the number of samples of 5 containing exactly one nonconforming chip is closest to:

Answer 1

Because 10 out of 140 chps do not conform to customer requirements, the probability of having a defective chip is
p = 10/140 = 0.0714
The probability of having a good chip is
q = 1 - p = 0.9286

Out of a sample of 5, the probability of finding a defective chip is
₅C₁ p¹ q⁴ = 5*0.0714*0.9286⁴ = 0.2655

The number of defective chips ofu of 5 is 0.2655*5 = 1.3275 ≈ 1

Answer : 1 chip