Psych 311 Exam Questions With New Update Solutions A+ Pass

Psych 311 Exam Questions With New Update Solutions A+ Pass A news poll showed that voters had no preference for any of the three candidates. In this example, the probability of a vote for, say, Candidate A equals A) 1/2 B) 1/3 C) 2/3 D) 1.00 - Answer- 1/3 Suppose that the probability that any child of alcoholic parents becomes alcoholic is p = .16. Assuming independent outcomes, the probability that two children of alcoholic parents will be alcoholic equals A) .16 B) .32 C) .03 D) .25 - Answer- .03 Two outcomes are said to be mutually exclusive when A) the probability of the two outcomes occurring together is equal to zero (p = 0) B) the probability of the occurrence of one outcome has no effect on the probability of the occurrence of the second outcome C) the probability of the two outcomes occurring together is greater than zero (p > 0) D) the probability of the two outcomes occurring together sums to one - Answer- the probability of the two outcomes occurring together is equal to zero (p = 0) The proportion or fraction of times an outcome is likely to occur is referred to as A) probability B) a random event C) sample space D) luck - Answer- probability A therapist goes through her records and finds that 200 of her 400 patients showed significant improvement in mental health over the past year. Hence, the probability of her patients showing significant improvement in mental health is A) .05 B) .50 C) 200 D) 400 - Answer- .50 A researcher records the following data for the number of bids made on a sample of items sold at an auction. Based on the table, what was the probability that an item had 7 bids made on it? Number of Bids Frequencies 3 5 4 12 5 7 6 6 7 10 A) 5 B) 10 C) .10 D) .25 - Answer- .25 Which of the following is NOT a characteristic of probability? A) Probability varies between 0 and 1. B) Probability can never be negative. C) Probability can be stated as a fraction or decimal. D) Probability is most useful for describing fixed events. - Answer- Probability is most useful for describing fixed events. In a game, the probability of winning money is p = .16, the probability of losing money is p = .54, and the probability of breaking even is p = .30. What is the probability of winning or losing money in this game? A) .16 B) .54 C) .70 D) 1.00 - Answer- .70 Which rule states that when two outcomes are independent, the probability that these outcomes occur together is the product of their individual probabilities? A) additive rule B) multiplicative rule C) both A and B D) none of the above - Answer- multiplicative rule A researcher reports that the probability of a college student living on campus is p = .38. If a small local college has 2,000 students enrolled, then what is the standard deviation of college students living on campus? Hint: This is a binomial probability distribution. A) 471.2 students B) 21.7 students C) 760 students D) There is not enough information to answer this question. - Answer- 21.7 students A researcher determines that the probability of missing class among students at a local school is p = .16. Assuming that the school has 300 students enrolled, how many students can we expect to miss class on a given day? Hint: This is a binomial probability distribution. A) 252 students B) 48 students C) 16 students D) There is not enough information to answer this question. - Answer- 48 students Each of the following is an example of a binomial distribution, except A) the number of heads in ten flips of a fair coin B) the number of males and females in a sample C) the number of votes for or against a candidate D) the time it takes to complete a driving test - Answer- the time it takes to complete a driving test If the standard deviation of a probability distribution is 9, then the variance is A) 3 B) 9 C) 81 D) unknown - Answer- 81 When the probability of one outcome changes depending on the occurrence of a second outcome, these outcomes are referred to as A) mutually exclusive B) complementary C) independent D) conditional - Answer- conditional The probability of a college student being employed is p = .35. The probability of a student being employed and dropping out of college is p = .20. Hence, the probability of a student dropping out of college, given that he or she is employed, is A) p = .07 B) p = .57 C) p = .55 D) There is not enough information to answer this question. - Answer- p = .57 Bayes' theorem is often applied to a variety of ________ probability situations, including those related to statistical inference. A) generic B) absolute C) conditional D) Fixed - Answer- conditional