Originally Posted by

**somestudent2** Another problem I am working on:

A survey of consumers in a particular community showed that 10% were dissatisfied with plumbing jobs done in their homes. Half the complaints dealt with plumber A. If plumber A does 40% of the plumbing jobs in the

town, find the following probabilities:

(a) A consumer will obtain an unsatisfactory plumbing job, given that the plumber was A.

(b) Consumer will obtain a satisfactory plumbing job, given that the plumber was A.

Solution

a)

I defined 2 events A and B

A: obtain unsatisfactory plumbing

B: the plumber is A

I am not sure if I find the right P(A and B) for the conditional prob.

Thats what I got:

P(A)= 40% or 0.4 P(B)=10% or 0.1

P(A|B)= 0.05/0.4 = 12.5%

b)

100-12.5=87.5%

Am I on the right track? Thanks