Quiz 4 Please refer to the following for the questions 1-4 Given that the heights of adult males show a mean of 69" and standard deviation 2.7." A sample of 37 adult males shows a mean of 68.2" and standard deviation of 2.9." 1. Which of the following is a statistic? a) 69 b) 2.7" c) 68.2 d) 37 2. Which of the following is a parameter? a. 2.9" b. 2.7" c. 68.2" d. 3: . Which of the following shows / , A , and S in this order? a. 69" 2.7" 68.2" 2.9" . 69" 68.2" 2.9" 2.7" c. 69" 68.2" 2.7" 2.9" d. 68.2" 69" 2.7" 2.9" Atul N Roy Page 1 . What is the standard deviation of the sample means of all simple random samples of size 37 from this population? 3) 2.7" b) 2.9" c) 0.44" d) 0.07" 5. The contents of a certain medication bottle show a normal distribution with a mean of 250 ml. and standard deviation of 5 ml. What is the probability that the mean of the contents in a simple random sample of 4 such bottles will be less than 245 ml? a) 0.16 b) 0.8 c) 0.023 d) 0.0003 Refer to the following statement for the questions 6 - 7 The time that it takes for a search committee member to review an application for a certain job shows a mean of 15 minutes and standard deviation of 10 minutes. 6. Which of the following is correct for the shape of the distribution of the review time? ) The shape of the distribution is normal. b) The shape of the distribution is not normal because time is not a continuous random variable. ) The shape of the distribution is not normal because about 6.7% of the values in a normal distribution with mean 15 and standard deviation 10 will be negative values. d) Nothing is normal these days. 7. Jim has to review 50 such applications. If these 50 may be treated as a simple random sample from the population of Atul N Roy Page 2 all such applications, the probability that Jim will have to spend more than a total of 15 hours to review these applications is ) 0.50 b) 0.017 c) 0.382 d) 0.618 Refer to the following for 8-10 Given that 6% of the 10000s of gadgets produced by a company have defective parts in them. A departmental store-chain is expecting a supply of 500 such gadgets. 8. If we take simple random samples of size 500 from the population of all such gadgets, the proportion of defectives among all such samples will show a mean of a) 30 b) 0.06 c) 0.96 d ) 6 9. If we take simple random samples of size 500 from the population of all such gadgets, the proportion of defectives among all such samples will show a standard deviation of a) 0.06 b ) 0.96 c) 0.0106 () 0.0011 Atul N Roy Page 3 10. If we take a simple random sample of 500 from the population of all such gadgets, the probability that more than 40 of these 500 will be defective is closest to a) 0.06 b) 0.08 c) 0.92 d) 0.0296 Atul N Roy Page 4