An investment newsletter writer wanted to know in which investment areas his subscribers were most interested. A questionnaire was sent to 331 randomly selected professional clients, with the following results:
Investment Area
Business Stocks Bonds Commercial Paper Commodities Stock Options Total
Doctors 30 25 15 2 0 72
Lawyers 29 34 12 0 5 80
Bankers 50 35 29 5 10 129
Others 21 14 10 3 2 50
331
a) What is the probability that an investment client is neither a doctor nor a lawyer?
b) What is the probability that an investment client is a banker and the investment client's main investment interest is in commodities?
c) If an investment client's main investment interest is in commodities, what is the probability that he/she is a banker?
d) What is the probability that an investment client's main investment interest is not in stock options?
e) Let A be the event that an investment client is a lawyer. Let B be the event that an investment client's main investment interest is in commodities. Are the events A and B mutually exclusive?