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

Exercise 36

Psychology: Myers-Briggs Approximately 75% of all marketing personnel are extroverts, whereas about 60% of all computer programmers are introverts (Source: A Guide to the Development and Use of the Myers-Briggs Type Indicator , by Myers and McCaulley).
(a) At a meeting of 15 marketing personnel, what is the probability that 10 or more are extroverts What is the probability that 5 or more are extroverts What is the probability that all are extroverts
(b) In a group of 5 computer programmers, what is the probability that none are introverts What is the probability that 3 or more are introverts What is the probability that all are introverts