1. A recent survey of 1070 U.S. adults selected at random showed that 669 consider the occupation of firefighter to have very great prestige. Estimate the probability (to the nearest hundredth) that a U.S. adult selected at random thinks the occupation of firefighter has very great prestige.

2.Consider the probability distribution shown below.

x	0	1	2
P(x)	0.75	0.20	0.05

a. Compute the expected value of the distribution. b. Compute the standard deviation of the distribution. (Round your answer to four decimal places.)

3. Consider a binomial experiment with n = 4 trials where the probability of success on a single trial is p = 0.45. (Round your answers to three decimal places.)

(a) Find

P(r = 0).

(b) Find

P(r 1)

by using the complement rule.

4. Consider a binomial experiment with n=6trials where the probability of success on a single trial is

p=0.20. (Round your answers to three decimal places.)

(a) Find

P(r= 0).

(b) Find

P(r1)

by using the complement rule.

5. A fair quarter is flipped three times. For each of the following probabilities, use the formula for the binomial distribution and a calculator to compute the requested probability. Next, look up the probability in the binomial probability distribution table. (Enter your answers to three decimal places.)

(a) Find the probability of getting exactly three heads. (b) Find the probability of getting exactly two heads. (c) Find the probability of getting two or more heads. (d) Find the probability of getting exactly three tails.

6. Richard has just been given a 4-question multiple-choice quiz in his history class. Each question has five answers, of which only one is correct. Since Richard has not attended class recently, he doesn't know any of the answers. Assuming that Richard guesses on all four questions, find the indicated probabilities. (Round your answers to three decimal places.)

(a)What is the probability that he will answer all questions correctly?

(b)What is the probability that he will answer all questions incorrectly?

(c)What is the probability that he will answer at least one of the questions correctly? Compute this probability two ways. First, use the rule for mutually exclusive events and the probabilities shown in the binomial probability distribution table.

(d) Then use the fact that P(r 1) = 1 P(r = 0).

(e) What is the probability that Richard will answer at least half the questions correctly?

7. Richard has just been given a8-question multiple-choice quiz in his history class. Each question has five answers, of which only one is correct. Since Richard has not attended class recently, he doesn't know any of the answers. Assuming that Richard guesses on alleightquestions, find the indicated probabilities. (Round your answers to three decimal places.)

(a)What is the probability that he will answer all questions correctly?

(b)What is the probability that he will answer all questions incorrectly?

(c)What is the probability that he will answer at least one of the questions correctly? Compute this probability two ways. First, use the rule for mutually exclusive events and the probabilities shown in thebinomial probability distribution table.

(d) Then use the fact thatP(r1) = 1P(r= 0).

(e) What is the probability that Richard will answer at least half the questions correctly?