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Unformatted text preview: hat is the probability that all students in a simple random sample of 15 students own a cell phone? 0 0.1 0.206 0.9 67. A) B) C) D) E) Which of the following is (are) NOT properties of a binomial setting for sample counts? I. The observations are all independent. II. Each observation is categorized as being a either success or a failure. III. The product of n and p must be at least 10. IV. The probability of a success is the same for each observation. I II III IV All of the above are required properties of the binomial setting. 68. A) B) C) D) E) 69. A) B) C) D) E) A production process, when functioning as it should, will still produce 2% defective items. A random sample of 10 items is to be selected from the 1000 items produced in a particular production run. Let X be the count of the number of defective items found in the random sample. What can be said about the variable X? We can use a Normal distribution with mean 20 and standard deviation 4.43 as an approximation for the distribution of X. X is approximately Normal with μ = 10 and σ = 0.44. X has an approximate binomial distribution with parameters 1000 and 0.01. X has an approximate binomial distribution with mean 0.2 and standard deviation 0.443. Without additional information we are unable to determine if X is approximately Normally distributed or if it has a binomial distribution. Let X be a random variable, which has a binomial distribution with mean μ = 8 and standard deviation σ = 2.19. The parameters n and p for this binomial distribution are respectively n = 16, p = 0.5. n = 13.3, p = 0.6. n = 10, p = 0.8. n = 20, p = 0.6. n = 20, p = 0.4. Use the following to answer questions 77 and 71: It is claimed that 55% of marriages in the state of California end in divorce within the first 15 years. A large study was started 15 years ago and has been tracking hundreds of marriages in the state of California. 70. A) B) C) D) Suppose ten marriages are randomly selected. What is the probability that less than two of them ended in a divorce? 0.0021 0.0045 0.0130 0.0274 15 J Diaco Elements of Statistics I Supplemental Final Exam Review 71. A) B) C) D) Suppose 100 marriages are randomly selected. What is the probability that less than 20 of them ended in a divorce? Less than 0.0001 0.0055 0.0130 0.0229 Use the following to answer questions 72–74: The scores of individual students on the American College Testing (ACT) Program Composite College Entrance Examination have a Normal distribution with mean 18.6 and standard deviation 6.0. At Northside High, 36 seniors take the test. Assume the scores at this school have the same distribution as national scores. 72. A) B) What is the mean of the sampling distribution of the sample mean score for a random sample of 36 students? 1.0 C) 6.0 3.1 D) 18.6 73. A) B) What is the standard deviation of the sampling distribution of the sample mean score for a random sample of 36 students? 1.0 C) 6.0 3.1 D) 18.6 74. A) B) C) D) What is the sampling distribution of the sample mean score for a random sample of 36 students?
Approximately Normal, but the approximation is poor. Approximately Normal, and the approximation is good. Exactly Normal. Neither Normal nor nonNormal. It depends on the particular 36 students selected. Use the following to answer questions 75–77: Chocolate bars produced by a certain machine are labeled 8.0 oz. The distribution of the actual weight...
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- Summer '09