MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

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1 AP Stats: Test Review - Chapters Name Period MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. Find the expected value of the random variable. Round to three decimal places. 1) The number of golf balls ordered by customers of a pro shop has the following probability distribution. x p(x) ) A) 7.98 B) 5.73 C) 9 D) 9.12 E) 8.4 Create a probability model for the random variable. 2) An insurance policy costs $200, and will pay policyholders $10,000 if they suffer a major injury (resulting in hospitalization), or $5,000 if they suffer a minor injury (resulting in lost time from work). The company estimates that each year 1 in every 2,500 policyholders may have a major injury, and 1 in 1,000 a minor injury. Create a probability model for the company's profit on this policy. A) Profit $200 $10,200 $5,200 2) B) C) D) E) Profit $200 $10,000 $5,000 Profit $200 - $9,800 -$4,800 Profit $200 -$10,200 -$5,200 Profit $200 $9,800 $4,800 Find the expected value of the random variable. Round to three decimal places. 3) A carnival game offers a $100 cash prize for anyone who can break a balloon by throwing a dart at it. It costs $8 to play and you're willing to spend up to $32 trying to win. You estimate that you have a 10% chance of hitting the balloon on any throw. Find the expected amount you will win. Assume that throws are independent of each other. 3) A) -$11.52 B) $9.27 C) $6.88 D) -$ E) $

2 Find the standard deviation of the random variable. Round to two decimal places if necessary. 4) The probability model below describes the number of thunderstorms that a certain town may experience during the month of August. 4) Number of storms Probability What is the standard deviation of the number of storms in August? A) 0.62 B) 0.64 C) 0.78 D) 0.73 E) 0.55 Create a probability model for the random variable. 5) A company is interviewing applicants for managerial positions. They plan to hire two people. They have already rejected most candidates and are left with a group of 11 applicants of whom 7 are women. Unable to differentiate further between the applicants, they choose two people at random from this group of 11. Let the random variable X be the number of men that are chosen. Find the probability model for X. A) P(Number men) B) P(Number men) C) P(Number men) D) P(Number men) E) P(Number men) ) Solve. 6) Given independent random variables with means and standard deviations as shown, find the mean and standard deviation of the variable 3Y - 9. Round to two decimal places if necessary. 6) Mean SD X Y A) μ = 480, σ = 51 B) μ = 480, σ = C)μ = 471, σ = 51 D) μ = 471, σ = E) μ = 471, σ = 42 2

3 7) Given independent random variables with means and standard deviations as shown, find the mean and standard deviation of the variable X + Y. Round to two decimal places if necessary. 7) Mean SD X 30 7 Y 60 5 A) μ = 90, σ = 12 B) μ = 90, σ = 8.60 C)μ = 90, σ = 74 D) μ = 1800, σ = 12 E) μ = 1800, σ = ) A company selling vegetable seeds in packets of 40 estimates that the mean number of seeds that will actually grow is 35.9 with a standard deviation of 1.6 seeds. If a customer buys 5 different seed packets, what are the expected value and standard deviation of the number of bad seeds? Assume that packets are independent of each other. 8) A) μ = 179.5, σ = 8 B) μ = 80.27, σ = 3.58 C)μ = 179.5, σ = 40 D) μ = 80.27, σ = 8 E) μ = 179.5, σ = ) In the relay event, each of four runners runs 100 meters. A college team is preparing for a competition. The means and standard deviations of the times (in seconds) of their four runners are shown in the table: 9) Runner Mean SD Find the probability that in the competition they will beat their previous best time of sec. Assume that the runners' performances are independent and that each runner's time follows a Normal model. A) B) C) D) E) ) Suppose a computer chip manufacturer rejects 3% of the chips produced because they fail presale testing. What is the probability that the seventh chip you test is the first bad one you find? 10) A) 0.03 B) C) D) E)

4 Round to four decimal places. 11) Suppose that 14% of people in one city speak Spanish. What's the probability that we won't find a person who speaks Spanish before the 6th person? 11) A) B) C) D) E) Solve. Round to two decimal places if necessary. 12) An archer is able to hit the bull's eye 68% of the time. If she keeps shooting arrows until she hits the bull's-eye, how long do you expect it will take? Assume each shot is independent of the others. 12) A) 68 shots B) 3.13 shots C) 0.68 shots D) 0.32 shots E) 1.47 shots 13) A multiple choice test has 10 questions each of which has 4 possible answers, only one of which is correct. If Judy, who forgot to study for the test, guesses on all questions, what is the probability that she will answer none of the questions correctly? 13) A) B) C) D) E) Find the probability of the outcome described. 14) A tennis player makes a successful first serve 60% of the time. If she serves 8 times, what is the probability that she gets no more than 3 first serves in? Assume that each serve is independent of the others. 14) A) B) C) D) E) ) A basketball player has made 70% of his foul shots during the season. If he shoots 5 foul shots in tonight's game, what is the probability that he misses at least once? Assume that shots are independent of each other. 15) A) 0.3 B) C) D) E) ) Police estimate that 25% of drivers drive without their seat belts. If they stop 4 drivers at random, find the probability that all of them are wearing their seat belts. 16) A) B) 0.75 C) 0.1 D) 0.3 E) Solve the problem. 17) In the town of Blues Valley, 8% of female college students suffer from manic-depressive illness. If 190 of the female students are selected at random, what is the mean of the number who suffer from manic-depressive illness? 17) A) 95 B) C) 15.2 D) 3.74 E) ) Suppose that 1.8% of people are left handed. If 40 people are selected at random, what is the standard deviation of the number of right-handers in the group? 18) A) B) 0.85 C) 0.84 D) 6.27 E)

5 Answer Key Testname: CH 17 REVIEW QUESTIONS PT 1 1) E 2) C 3) C 4) C 5) A 6) C 7) B 8) E 9) B 10) B 11) B 12) E 13) C 14) C 15) B 16) A 17) C 18) C 5

Record on a ScanTron, your choosen response for each question. You may write on this form. One page of notes and a calculator are allowed.

Ch 16, 17 Math 240 Exam 4 v1 Good SAMPLE No Book, Yes 1 Page Notes, Yes Calculator, 120 Minutes Dressler Record on a ScanTron, your choosen response for each question. You may write on this form. One page