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AP Stats Unit IV (Chapters 14-17) Take-Home Test Info The practice test follows this cover sheet. It is very similar to the “real” Chapter 14-17 Test. The real test will… • consist of 20 multiple-choice questions (Section I) • consist of three shorter free-response questions (Section II, Part A) • consist of one more involved free-response question (Section II, Part B) • be emailed to you Tuesday evening, March 9, 2010 • be due at class time Tuesday, March 16 / Wednesday, March 17, 2010 . Similar to the last take-home test, you may work with anyone else in your class or the other class. In fact – you SHOULD plan on working with each other! You must accomplish the exact version of the test that will be emailed to you! Turning in answers to a different version will be considered academic dishonesty. I will be available in room 141 Monday evening, March 15, from 6:30 – 8pm for assistance with this Practice Test only. I will NOT be answering questions on the real test. Good luck. ☺

AP Stats Chap 14 – 17 Practice Test SECTION I Number of Questions – 20 Percent of Total Grade – 50 Directions: Solve each of the following problems, using the available space (or extra paper) for scratchwork. Decide which is the best of the choices given and place that letter on the ScanTron sheet. No credit will be given for anything written on these pages for this part of the test. Do not spend too much time on any one problem. 1. Which two events are most likely to be independent? A. having a flat tire, and being late for school B. getting an A in math, and getting an A in Physics C. having a driver’s license, and having blue eyes D. having a car accident, and having three inches of snow today E. being a senior, and leaving campus for lunch 2. Political analysts estimate the probability that Hillary Clinton will run for president in 2008 is 45% and the probability that New York’s Governor George Pataki will run as the Republican candidate is 20%. If their political decisions are independent, then what is the probability that only Hillary runs for president? A. 9% B. 11% C. 25% D. 36% E. 45% 3. In an AP Stats class, 57% of students eat breakfast in the morning and 80% of students floss their teeth. Forty-six percent of students eat breakfast and also floss their teeth. What is the probability that a student from this class eats breakfast but does not floss his/her teeth? A. 9% B. 11% C. 34% D. 57% E. 91% 4. The city council has six men and three women. If we randomly choose two of them to co-chair a committee, what is the probability these chairpersons are the same gender? A. 4/9 B. 1/2 C. 5/9 D. 5/8 E. 7/8 5. Which of these random variables has a geometric model? A. the number of cards of each suit in a ten-card hand B. the number of people we check until we find someone with green eyes C. the number of cars inspected until we find three with bad mufflers D. the number of Democrats among a group of 20 randomly chosen adults E. the number of aces among the top ten cards in a well-shuffled deck 6. You are dealt a hand of three cards, one at a time. Find the probability that your cards are all diamonds. A. 0 . 750 B. 0 . 705 C. 0 . 013 D. 0 . 016 E. 0 . 231 0 I / of 0 brush floss 0 0 :-( 㱺 + E) # 302-+8-2 = 3 ¥ 3 ¥ = I 0 0 ( 㱺 ( ¥ ) (1-50)--0.013

14. Police estimate that in one city 59% of drivers wear their seat belts. They set up a safety roadblock, stopping cars to check for seat belt use. If they stop 30 cars during the first hour, what is the mean number of drivers expected to be wearing their seat belts? A. 7 . 26 B. 12 . 3 C. 2 . 69 D. 15 E. 17 . 7 15. On a multiple choice test with 13 questions, each question has four possible answers, one of which is correct. For students who guess at all the answers, find the standard deviation of the number of correct answers. A. 1 . 5 B. 1 . 53 C. 1 . 875 D. 1 . 561 E. 1 . 47 16. A laboratory worker finds that 1 . 6% of his blood samples test positive for the HIV virus. If 240 blood samples are selected at random, is it appropriate to use a Normal model to approximate the distribution of the number that test positive for the virus? A. No. A Normal model cannot be used to approximate the distribution because nq < 10. B. Yes. A Normal model with μ = 3 . 84 and σ = 3 . 78 can be used to approximate the distribution. C. No. A Normal model cannot be used to approximate the distribution because np <10. D. Yes. A Normal model with μ = 236 . 16 and σ = 1 . 94 can be used to approximate the distribution. E. Yes. A Normal model with μ = 3 . 84 and σ = 1 . 94 can be used to approximate the distribution. 17. A tennis player usually makes a successful first serve 73% of the time. She buys a new racket hoping that is will improve her success rate. During the first month of playing with her new racket, she makes 327 successful first serves out of 410. Is this evidence that with the new racket her success rate has improved? In other words, is this an unusual result for her? A. Yes. We would normally expect her to make 299 . 3 first serves with a standard deviation of 80 . 81. 327 is 0 . 3 standard deviations above the expected value. That’s an unusual result. B. No. We would normally expect her to make 299 . 3 first serves with a standard deviation of 80 . 81. 327 is 0 . 3 standard deviations above the expected value. That’s not an unusual result. C. Yes. We would normally expect her to make 299 . 3 first serves with a standard deviation of 8 . 99. 327 is 3 . 1 standard deviations above the expected value. That’s an unusual result. D. No. We would normally expect her to make 299 . 3 first serves with a standard deviation of 17 . 30. 327 is 1 . 6 standard deviations above the expected value. That’s not an unusual result. E. No. We would normally expect her to make 299 . 3 first serves with a standard deviation of 8 . 99. 327 is 3 . 1 standard deviations above the expected value. That’s not an unusual result. - ① bison -_ 306.59 )= - p -0.25 g- 0-75 0 toasts - " so 24010.0163=3.84--10 RPZIO ngaio 0 0 EC= µ =op= 4100.733--299.3+28.95--316 SD - ¥ FÉ3CÑD= 8.9s so

18. 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. A. $9 . 27 B. $6 . 88 C. $14 . 88 D. -$11 . 52 E. -$638 . 73 19. Your favorite soccer team, Mill Valley, plays two games against Fairfield. The probability that your team wins the first game is 0 . 4. If your team wins the first game, the probability that they also win the second game is 0 . 4. If your team loses the first game, the probability that they win the second game is 0 . 2. Let the random variable X be the number of games won by your team. Find the standard deviation of X. A. 0 . 54 B. 0 . 84 C. 0 . 63 D. 0 . 69 E. 0 . 73 20. A manufacturing process has a 70% yield, meaning 70% of the products are acceptable and 30% are defective. If three of the products are randomly selected, find the probability that all of them are acceptable. A. 0 . 027 B. 0 . 429 C. 0 . 343 D. 2 . 1 E. 0 . 9 SECTION II Part A 3 Questions (similar to the following) Percent of Section II Grade – 75 SECTION II Part B 1 Question (similar to the following) Percent of Section II Grade – 25 Directions: Show all of your work. Indicate clearly the methods you use, because you will be graded on the correctness of your methods as well as on the accuracy of your results and explanations. Traffic Accidents. 21. Police reports about the traffic accidents they investigated last year indicated that 40% of the accidents involved speeding, 25% involved alcohol, and 10% involved both risk factors. a. What is the probability that an accident involved neither alcohol nor speed? b. Do these two risk factors appear to be independent? Explain using statistical evidence. t.to ? to.o ? t.oIt-:. 92 84 98 68 -32 Blood +2010.09+390.08131-4%0.0>2%-4*0065613--40777 Ooga , - 0.4=0.16 - lose win 0-4-0.6=0-24 ] - in ① 0.2--0-12 lose 0.6=0.8--0.48 10th - = - ° binompdf (3,0-73)=343-4 - PCA )=P(A1D= ¥ ^§= 8%7--0.25--0.25 alcohol 4010 ÷÷i 45% 486 Yes , b/c PCAIS )=PCA ) (0.25--0.25) .