Question 18 of 36 - 1 E An ofce supply company conducted a survey before marketing a new paper shredder designed for home use. In the survey, 80% of people who used the shredder were satised with it. Because of this high acceptance rate. the company decided to market the new shredder. Assume that 80% of all people who use it will be satised. On a certain day, seven customers bought this shredder. a. Let x denote the number of customers in this sample of seven who will be satised with this shredder. Using the binomial probabilities table. obtain the probability distribution of x and ll in the table below. Round your answers to four decimal places. I P (x) 65 1 M Find the mean and standard deviation of x. Enter the exact answer for the mean. and round the standard deviation to three decimal places. i customer(si (T = customeris] Question 19 of 36 - f 1 i: E Viewr Policies Current Attempt in Progress Dennis made a 340 on the AA'I'. a standardized test with a known normal distribution having a mean of 400 and a standard deviation of 20. Sharon made a 12 on the SCT, another standardized test with a known normal distribution having a mean of 18 and a standard deviation of 3. Who did worse? v Question 20 of 36 - l 1 E E _.... -.... .---...... . . -.. --- Indicate which of the following random variables are discrete and which are continuous. a. The number of new accounts opened at a bank during a certain month: V b. The time taken to run a marathon: v c. The price of a concert ticket: v d. The number of rotten eggs in a randomly selected box: v e. The points scored in a football game: v f. The weight of a randomly selected package: v Question 21 of36 -:' 1 '5 View Policies Current Attempt in Progress Let x be a continuous random variable that has a normal distribution with n u = 89 and o- = 19. Assuming F 5 0.05, fInd the probability that the sample mean. 2, for a random sample of 22 taken from this population will be between 84.3 and 98.2. Round your answer to four decimal places. Question 22 of 36 - I 1 E View Policies Current Attempt in Progress Let x be a continuous random variable that has a normal distribution with P? ,u = 75 and a = [3. Assuming E g 0.05, nd the probability that the sample mean, E, for a random sample of 15 taken from this population will be less than 68.3. Round your answer to four decimal places. one Question 23 of 36 -11 :2 View Policies Current Attempt in Progress The GPAs of all students enrolled at a large university have an approximately normal distribution with a mean of 3.02 and a standard deviation of 0.29. Find the probabi Iitv that the mean GPA of a random sample of 20 students selected from this university is 3.07 or higher. Round your answer to four decimal places. P(Y 2 3.07) = Question 24 of 36 -1 1 := View Policies Current Attempt in Progress The GPAs of all students enrolled at a large university have an approximately normal distribution with a mean of 3.02 and a standard deviation of 0.29. Find the probability that the mean GPA of a random sample of 20 students selected from this university is 2.89 or lower. Round your answer to four decimal places. PG 5 2.89) = no Question 25 of 36 - 11 3 View Policies Current Attempt in Progress Consider Ht]: :4 = 45 versus H]: ,u I '55 _l. a... I\" no. View Policies Current Attempt in Progress According to an estimate, 2 years ago the average age of all CEOs of medium- sized companies in the United States was 58 years. Jennifer wants to check if this is still true. She took a random sample of 70 such CEOs and found their mean age to be 55 years with a standard deviation of 6 years. Using the 1% signicance level. can you conclude that the current mean age of all CEOS of medium-sized companies in the United States is different from 58 years? Question 27 of 36 - M View Policies Current Attempt in Progress A real estate agent claims that the mean living area of all single-family homes in his county is at most 2400 square feet. A random sample of 50 such homes selected from this county produced the mean living area of 2598 square feet and a standard deviation of 472 square feet. Using a = 0.05. can you conclude that the real estate agent's claim is true? V Question 28 of 36 -f1 View Policies Current Attempt in Progress A manager is deciding on next year's raises, so she looks at performance review scores. Abigail has had 7 annual reviews. with an average score of 8.5 {out of 10. where 10 is best} with a standard deviation of 0.5. Brian has had 11 performance reviews. and has an average of 8.9 with a standard deviation of 1.1. Is Abigail's performance signicantly worse at a = 0.05 than Brian's? v no. Question 29 of 36 - f 1 25 View Policies Current Attempt in Progress An auto manufacturing company wanted to investigate howr the price of one of its car models depreciates with age. The research department at the company took a sample of eight cars of this model and collected the following information on the ages [in years) and prices {in hundreds of dollars] of these cars. 22437835 Price 89 TH 59 69 43 29 78 56 Find the regression line equation in the form 3': = a + bx. Use "Age" as the independent variable a nd "Price" as the dependent variable. Round your answers to four decimal places. h J}: I +( E )x Question 30 of 36 - 1' 1 E Current Attempt in Progress The following table gives information on the amount of sugar [in grams) and the calorie count in one serving of a sample of 13 varieties of Kellogg's cereal. 2{] Ilium-"Illa m- m { The regression equation of the number of calories on the amount of sugar is 3; = 83.054 + 5.297x. where x is amount of sugar {in grams] and y is calories. 19!! Calculate the predicted calorie count for a cereal with 13 grams of sugar per serving. Round your answer to the nearest integer. calories Question 31 of 36 - {1 E on. View Policies Current Attempt in Progress A men's clothing store has been getting more requests for tall clothes, and the manager decides to see if the average customer is actually taller. From store records. he knows that the average height of customers ve years ago was 71 inches. He randomly samples 20 customers over the next few days and nds that their average height is 72 inches. with a standard deviation of 3 inches. Is there evidence that this store's customers are taller than theyI were ve years ago? (Use a = 0.05. } v Question 32 of 36 _ H 1: View Policies Current Attempt in Progress The prices of all college textbooks fol low a bell~shaped distribution with a mean of $ I 80 and standard deviation of $30. Using the empirical rule, nd the percentage of all college textbooks with their prices between $90 to $210. Enter the exact answer. 96 Question 33 of 36 - I 1 if View Policies Current Attempt in Progress The following data give the speeds of 13 cars (in mph} measured by radar, travelling on l-B4. 73 75 69 68 73 69 74 76 72 79 68 77 71 Compute the percentile rank of 75. Round your answer to two decimal places. 96 1 Question 34 of 36 - I 1 :: View Policies Current Attempt in Progress The following data give the money {in dollars] spent on textbooks during the Fall 2015 semester by 35 students selected from a university. 565 728 870 620 349 868 610 765 550 345 530 705 488 263 320 505 957 787 617 721 635 438 575 702 538 720 460 840 890 560 570 706 430 965 639 a. Prepare a stern-and-leaf display for these data using the last two digits as leaves. 5 05 30 38 50 60 65 7O 75 6 10 17 20 35 39 7 02 05 06 2D 21 28 65 87 8404568 70 90 b. Condense the stem-and-Ieaf display by grouping the stems as 2-4, 5-6. and 7- 9. 2-463 * 2049 * 303360" 56 05 30 38 so so 65 70 75 * 1o 17 20 35 I 790205062021286587'4045687090'57n ' t Question 35 Current Attempt in Progress At Jen and Perry Ice Cream Company, the machine that fills 1pound cartons of Top Flavor ice cream is set to dispense 16 ounces of ice cream into every carton. However. some cartons contain slightly less than and some contain slightly more than 16 ounces of ice cream. The amounts of ice cream in all such cartons have a normal distribution with a mean of 16 ounces and a standard deviation of 0.42 ounces. Find the probability that a randomly selected carton contains 16.015 to 16.025 ounces of ice cream. Round your answer to four decimal places. P: Question 36 of 36 -! 1 ;: View Policies Current Attempt in Progress Aconstruction zone on a highway has a posted speed limit of 45 miles per hour. The speeds of vehicles passing through this construction zone are normally distributed with a mean of 39 miles per hour and a standard deviation of 4 miles per haur. Find the percentage of vehicles passing thmugh this construction zone that are exceeding the posted speed limit. Round your answer to two decimal places. The percentage is %