What are the chances that a person who is murdered actually knew the murderer? The answer to this question explains why a lot of police detective work begins with relatives and friends of the victim!...

What are the chances that a person who is murdered actually knew the murderer? The answer to this question explains why a lot of police detective work begins with relatives and friends of the victim! About 61% of people who are murdered actually knew the person who committed the murder.† Suppose that a detective file in New Orleans has 68 current unsolved murders. Find the following probabilities. (Round your answers to four decimal places.)

(b) at most 48 of the victims knew their murderers

(c) fewer than 30 victims did not know their murderers

(d) more than 20 victims did not know their murderers