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

Exercise 12

Criminal Justice: Convictions Innocent until proven guilty In japanese criminal trails, about 95% of the defendants are found guilty. In the United States, about 60% of the defendants are found guilty in criminal trials (Source: The Book of Risks , by Larry Laudan, John Wiley and Sons). Suppose you are a news reporter following seven criminal trials.
(a) If the trials were in Japan, what is the probability that all the defendants would be found guilty what is this probability if the trials were in the United States
(b) Of the seven trials, what is the expected number of guilty verdicts in Japan What is the expected number in the United States What is the standard deviation in each case