Chapter 6 Review Questions

Chapter 6 Review Questions Answer the following multiple choice questions: 1. The probability of any outcome of a random phenomenon is (a) The precise degree of randomness present in the phenomenon (b) Any number as long as it is between 0 and 1 (c) Either 0 or 1, depending on whether or not the phenomenon can actually occur or not (d) The proportion of an infinite number of repetitions on which the outcome occurs (e) None of the above 2. A randomly selected student is asked to respond to yes, no, or maybe to the question, “Do you intend to vote in the next presidential election?” The sample space is { yes, no, maybe }. Which of the following represent a legitimate assignment of probabilities for this sample space? (a) 0.4, 0.4, 0.2 (b) 0.4, 0.6, 0.4 (c) 0.3, 0.3, 0.3 (d) 0.5, 0.3, –0.2 (e) None of the above 3. If you choose a card at random from a well-shuffled deck of 52 cards, what is the probability that the card chosen is not a heart? (a) 0.25 (b) 0.50 (c) 0.75 (d) 1 (e) None of the above 4. You play tennis regularly with a friend, and from past experience, you believe that the outcome of each match is independent. For any given match you have a probability of .6 of winning. The probability that you win the next two matches is (a) 0.16 (b) 0.36 (c) 0.4 (d) 0.6 (e) 1.2 5. If P(A) = 0.24 and P(B) = 0.52 and A and B are independent, what is P(A or B)? (a) 0.1248 (b) 0.28 (c) 0.6352 (d) 0.76 (e) The answer cannot be determined from the information given 6. Which of the following pairs of events are disjoint (mutually exclusive)? (a) A: the odd numbers; B: the number 5 (b) A: the even numbers; B: the numbers greater than 10 (c) A: the numbers less than 5; B: all negative numbers (d) A: the numbers above 100; B: the numbers less than –200 (e) A: negative numbers; B: odd numbers 7. Which of the following are true? I. The sum of the probabilities in a probability distribution can be any number between 0 and 1. II. The probability of the union of two events is the sum of the probabilities of those events. III. The probability that an event happens is equal to 1 – (the probability that the event does not happen). (a) I and II only (b) I and III only (c) II and III only (d) I, II, and III (e) None of the above gives the complete set of true responses 8. Government data show that 26% of the civilian labor force has at least 4 years of college and that 15% of the labor force works as laborers or operators of machines or vehicles. Can you conclude that because (0.26)(0.15) = .039 about 4% of the labor force are college-educated laborers or operators? (a) Yes, by the multiplication rule (b) Yes, by conditional probabilities (c) Yes, by the law of large numbers (d) No, because the events are not independent (e) No, because the events are not mutually exclusive 9. If a peanut M&M is chosen at random, the chances of it being of a particular color are shown in the table below. Color Probability Brown .3 Red .2 Yellow .2 Green .2 Orange .1 The probability of randomly drawing a blue peanut M&M is (a) 0.1 (b) 0.2 (c) 0.3 (d) 1.0 (e) According to this distribution, it’s impossible to draw a blue peanut M&M. 10. If A∪B = S (sample space), P(A and Bc) = 0.25, and P(Ac) = 0.35, then P(B) = (a) 0.35 (b) 0.4 (c) 0.65 (d) 0.75 (e) None of the above. The answer is ________________. Answers: 1. d 2. a 3. c 4. b 5. c 6. d 7. e 8. d 9. e 10. d Blue