1. Assume that 74% of randomly selected adults have a credit card ( based on an AARP Bulletin survey).

a) If 5 adults are randomly selected, what is the probability that exactly four of them have a credit card? {Round to nearest four decimal places.}

b) If 5 adults are randomly selected, what is the probability that at least one of them has a credit card? {Round to nearest four decimal places.}

c) Explain why the answer in part (b) is not valid if applied to five adults friends who are vacationing together?

2. On a multiple choice test with 22 questions, each question has four possible answers, one of which is correct. For students who guess at all answers, find the standard deviation ( rounded to the nearest 3 decimal places).