Question

At a certain auto parts manufacturer, the Quality Control division has determined that one of the machines produces defective parts 12% of the time. If this percentage is correct, what is the probability that, in a random sample of 7 parts produced by this machine, exactly 2 are defective

Answer 1

Answer:

Therefore the required probability is 0.15.

Step-by-step explanation:

Poisson distribution:

The Poisson distribution is the number of an event is occur within a time period.

$P(X=x)=\frac{e^{-\mu}\mu^x}{x!}$

μ= The mean

x= event.

In Poisson distribution , the average rate event per time period is constant.

12%  defective parts is produced by one of the machines of the time.

μ= (12%×7)= 0.84

x= the number of defective product =2

$P(X=2)=\frac{e^{-0.84}(0.84)^2}{2!}$

               =0.15

Therefore the required probability is 0.15.