Question

If 3% of the electric bulbs manufactured by a company are defective find the probability that in a sample of 100 bulbs exactly 5 bulbs are defective. Round the answer to 3 s.f

Answer 1

= Here, we have given that 3% of the electric bulbs manufactured by a company are defective.

i.e. prob. of a defective ball is 0.03

The sample size is 100 which is a large value.

This is a problem of binomial distribution but since n is large,

We know that if n is very large & p is very small, the distribution follows a Poisson distribution.

where the parameter of Poisson distribution, λ=n*p= 100*0.03= 3