Understanding Basic Statistics 6th Edition by Charles Henry Brase,Corrinne Pellillo Brase

تمرين 95

Crime: Murder 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 64% of people who are murdered actually knew the person who committed the murder ( Chances: Risk and Odds in Everyday Life , by James Burke). Suppose that a detective file in New Orleans has 63 current unsolved murders. What is the probability that
(a) at least 35 of the victims knew their murderers
(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