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week 9: TESt 7 Progress saved Done Score: 6143 6111 answered 15-. . Question 7 v b. For the group of 16, find the probability that the average number of friends is more than 149. c. Find the first quartile for the average number of Facebook friends. d. For part b), is the assumption that the distribution is normal necessary? C] YesC] No week 9: TESt 7 Progress saved Done Score: 6143 6X11 answered '45-. OI. . Question 8 v 87pm '01 82 Details The average number of miles (in thousands) that a car's tire will function before needing replacement is 70 and the standard deviation is 18. Suppose that 17 randomly selected tires are tested. Round all answers to 4 decimal places where possible and assume a normal distribution. a. What is the distribution of X? X - N([:], {:1} b. What is the distribution of i? i ~ N([:], {:1} c. If a randomly selected individual tire is tested, find the probability that the number of miles (in thousands) before it will need replacement is between 65.7 and 69.2. [: d. For the 17 tires tested, find the probability that the average miles (in thousands) before need of replacement is between 65.7 and 69.2. [:1 e. For part d), is the assumption that the distribution is normal necessary? [3 NCO Yes week 9: TeSt 7 Progress saved Done Score: 6/43 6/11 answered 15-. II. 0 Question 9 v 810 pts '01 82 (Doe-tails The average score for games played in the NFL is 20.5 and the standard deviation is 9.3 points. 14 games are randomly selected. Round all answers to 4 decimal places where possible and assume a normal distribution. a. What is the distribution of 5:? 5-, ~ N([:], [3) b. What is the distribution of Z 3:? Z 3: ~ N( SIC} c. Pli 251.6052) = [:] h. For part c) and e), is the assumption of normal necessary? C] NOD Yes week 9: TESt 7 Progress saved Done Score: 6143 62'11 answered \\l-O . Question 10 v then the sampling distribution is b. Suppose that 39 classes are clocked. What is the distribution of 5: for this group of classes? 3; ~ N( --> c. What is the probability that the average of 39 classes will end with the second hand between 27 and 34 week 9: TeSt 7 Progress saved Done Score: 6143 62'11 answered \\l-O OI. 0 Question 11 v 810 pts '01 82 Details The average score for games played in the NFL is 20.6 and the standard deviation is 9 points. 43 games are randomly selected. Round all answers to 4 decimal places where possible and assume a normal distribution. a. What is the distribution of 5:? 5: - N([:], [:i) b. What is the distribution of Z 3:? Z :1: ~ N( [:lCl .. P(i 835.9759) = [: h. For part c) and e), is the assumption of normal necessary? C] NoC] Yes
