Criminal Justice: Parole USA Today reports that about 25% of all prison parolees become repeat offenders. Alice is a social worker whose job is to counsel people on parole. Let us say success means a person does not become a repeat offender. Alice has been given a group of four parolees.

(a) Find the probability P(r) of r successes ranging from 0 to 4.

(b) Make a histogram for the probability distribution of part (a).

(c) What is the expected number of parolees in Alice’s group who will not be repeat offenders? What is the standard deviation?