QUESTION 19 A utility company serves 50,000 households. As part of a survey of customer attitudes, they take a simple random of 800 of these households. The average number of television sets in the sample households turns out to be 1.91, and the SD is 0.64. Compute a 99.7% confidence interval for the average number of television sets in all 50,000 households. O (1.87, 1.95) (1.84, 1.98) (1.90, 1.92) (1.89, 1.93) QUESTION 20 A sample of 10 quality control managers with over 15 years of experience has an average salary of $54,000 and a standard deviation of $15,000. Assuming the distribution of the salary is normal, you can be 95% confident that the mean salary for all quality control managers with at least 15 years of experience is between what two numbers? OA (53141, 54234) B. (43269, 64731) OC (33269, 61915) O D. (40320, 62773) QUESTION 21 Marketing research consultant hired by Coca-cola is interested in determining the proportion of customers who favor Coke over other soft drinks. A random sample of 2000 consumers were selected from the market under investigation and showed that 53% favored Coca-Cola over other brands. Compute a 95% confidence interval for the true proportion of people who favor Coke. O A. (0.4811, 0.5789) O B. (0.4123, 0.5123) O C. (0.5081, 0.5519) O D. (0.3920, 0.5232)Z QUESTION 11 A. 68% A fair die is rolled 100 times. What is the chance that the proportion of odd numbers will be in the range from 0.35 to 0.65? (Hint: use 68-95-99.7% rule.) B. 99.7% O C. (99.7-95) /2% O D. 95% QUESTION 12 SD .). Suppose 50% of the students in a school are boys. What is the chance that in a randomly selected sample of 100 students, 53 are boys? (Note: N(M, o) is a normal random variable with mean u and O AP(N(50,5) = 53) O B. P ( 52.5s N (0.5,0.05) $ 53.5) c. P(N(0.5,0.05) = 53) O D. P ( 52.5 - N ( 50,5) $ 53.5) QUESTION 13 If you are spinning a color wheel with 7 colors on it and you have 100 spins to get a red. After 99 spins you have gotten every color but red. What is the chance you will spin a red on the 100th spin? O A. More than 1/7, but less than 6/7 B. 1/7 O C. 6/7 O D. 1/100 QUESTION 14QUESTION 14 Suppose X is the number of parking tickets that Tom will get in a year. Suppose X has the following probability distribution: O RI (X) N O What is the probability of Tom getting at most two parking tickets in a year? O A. 0.6 B. 0.7 OCO.4 O D.0.1 QUESTION 15 Suppose X is the number of parking tickets that Tom will get in a year. Suppose X has the following probability distribution: in m P(X) How many tickets does Tom expect to get in a year ? O A. O+ 1+ 2+3+4+5+6 OB.O OC 1+ 2+ 3+4+5 D. 0* 4+ 1 $2+2#1+3# 1+4#1+5#1QUESTION 16 A recent poll by Suolk University/USA Today based on a sample size of 1,000 likely voters reports that 49% favor Hilary Clinton (http://www.politico.com/2016-election/po tion/ national/2016-presidential-election-002637) . Suppose these 1,000 people are a random sample of likely voters. Then the margin of error of a 90% confidence interval for percentage of voters favoring Clinton is: (hint: in %, not in decimal)? Is/president/2016-elec A. 1.58% O B. 2.60% O C. 26.00% O D.0.26% QUESTION 17 following statements is TRUE? A simple random sample of 1000 persons is taken to estimate the percentage of graduates in a large population. It turns out that 513 of the people in the sample have graduated. Which of the O A. (48.2%, 54.4%) is a 95% confidence interval for the sample percentage. O B. (48.2%, 54.4%) is a 95% confidence interval for the population percentage. O C. There is a 95% chance for the percentage of graduates in the population to be in the range (48.2%, 54.4%). O D. The sample percentage is 51.3% and the SE for the sample percentage is 3.1% QUESTION 18 A university has 30,000 registered students. As part of a survey, 13 of these students are chosen at random. The average age of the sample students turns out to be 21.8 years, and the SD is 4.9 years. Find a 90%-confidence interval for the average age of all 30,000 registered students. O A. (19.38, 24.22) O B. (19.14, 24.46) O c. (19.56, 20.04) O D. (21.75, 21.85)