Spring 2015 Exam 3 Ch. 7, 8, 9, 10 Name.doc

Spring 2002 Exam 3: Ch. 7, 8, 9, 10 Name:_______________________ Questions 1, 2, and 3 refer to the following: In a study of a sample of 35 Computer Science majors and 40 Business majors, the average number of science fiction books each group read per year was recorded. The Computer Science majors read an average of 11 books with a standard deviation of 4 books. The Business majors read an average of 9 books with a standard deviation of 4.5 books. We are interested in whether the average number of science fiction books read by the Computer Science majors is the same as the number read by the Business majors. CS = Computer Science majors B = Business majors 1. The alternate hypothesis is: A. (CS = (B B. (CS ( (B C. (CS (B D. (CS (B 2. The exact distribution for the test is A. Normal B. Student-t with df ( 72.9775 C. Exponential D. Uniform 3. The p-value is A. 0.0452 B. 2.0376 C. 0.0226 D. 0 Questions 4 and 5 refer to the following. Suppose that a random survey of 10 teenagers found that the average amount of time they spend on the Internet each day is 3.2 hours with a sample standard deviation of 0.78 hours. 4. The point estimate of the population average amount of time teenagers spend on the Internet each day is A. 0.78 hours B. 32 hours C. 3.2 hours D. unknown 5. An 87% confidence interval for the average amount of time a teenager spends on the Internet each day would be A. (2.71, 3.68) B. (2.83, 3.57) C. (2.64, 3.76) D. (2.79, 3.61) 6. Which of the following is TRUE about a 99% confidence interval for the true average amount of time that teenagers spend on the Internet each day. We are 99% confident that the true average time that teenagers spend on the Internet per day lies within the confidence interval. The confidence interval contains 99% of the data values collected. 99% of all the confidence intervals constructed this way contain the true average amount of time teenagers spend on the Internet ea