An inspector randomly selects three parts from a lot that contains 3 defective and 4 nondefective parts. What is the probability that the inspector finds exactly 1 defective part?

For this case N = 7, M = 3, n =3, k=1

Step-by-step explanation:

Previous concepts

The hypergeometric distribution is a discrete probability distribution that its useful when we have more than two distinguishable groups in a sample and the probability mass function is given by:

Where N is the population size, M is the number of success states in the population, n is the number of draws, k is the number of observed successes  

The expected value and variance for this distribution are given by:

For this case N = 7, M = 3, n =3, k=1

Solution to the problem

For this case we want this probability:

and if we use the probability mass function we got:

if x = 1, then the answer is 3.5

answer: 1 + 1 = 11

step-by-step explanation: