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Question number 1. Your answer was E. Correct. A service center receives an average of 0.5 customer complaints per hour. Management's goal is to receive fewer than three complaints each hour. Assume the number of complaints follows the Poisson distribution. Determine the probability that exactly four complaints will be received during the next eight hours. A 0. B 0. C 1. D 0. E 0. Question number 2. Your answer was A. Correct. A random variable X has a probability distribution as follows: X 0 1 2 3 4 P( X ) 4 k 3 k 2 k 4 k 2 k What is P(X < 3)? A 3535
B 115115
C 13151315
D 11151115
E Cannot be determined. Question number 3. Your answer was B. A shipment of 15 televisions sets contains 4 defective sets. A hotel purchases 8 of these televisions sets. What is the probability that the hotel receives at least one of the defective sets? A 0. B 0. C 0. D 0. E 0. F None of the above.
C 0.
D 0.
E 0.
Question number 6. Your answer was D. Wrong. Rainwater was collected in water collectors at thirty different sites near an industrial basin and the amount of acidity (pH level) was measured. The mean and standard deviation of the values are 4.9 and 1.5 respectively. When the pH meter was recalibrated back at the laboratory, it was found to be in error. The error can be corrected by adding 0.2 pH units to all of the values and then multiply the result by 1.3. Find the mean and standard deviation of the corrected pH measurements. A mean = 2.28; standard deviation = 1. B mean = 6.57; standard deviation = 2. C mean = 6.63; standard deviation = 1. D mean = 2.28; standard deviation = 0. E mean = 6.63; standard deviation = 0. Question number 7.
Your answer was A. Wrong. John and Beth plan to visit a bookstore. Based on their previous visits to this bookstore, the probability distributions for the number of books they will buy is given below. Number of books John will buy 0 1 2 3 Probability 0.40 0.30 0.10 0. Number of books Beth will buy 0 1 2 3 Probability 0.30 0.20 0.15 0. Assuming that John and Beth make their decisions to purchase books independently, what is the probability that a total of 0 books are purchased? A 0. B 0. C 0. D 0. E 0. Question number 8. Your answer was A. Correct. This is a written question, worth 17 points. DO NOT place the problem code on the answer sheet. A proctor will fill this out after exam submission. Show all steps (work) on your answer sheet for full credit.
inventory contains 3000 units from Supplier S1, 5000 units from Supplier S2, and 2000 units from Supplier S3, which means if a part is randomly chosen from the inventory, there is 30% of the chance that this part is from Supplier S1, 50% of the chance that this part is from Supplier S2, and 20% of the chance that this part is from Supplier S3. Part a: Draw a tree diagram for this problem. Part b: If a part is chosen from the inventory at random, what is the probability that it is not defective? Part c: If a randomly selected part is defective, what is the probability that it is from Supplier S1? A I have placed my work and my answer on my answer sheet. B I want to have points deducted from my test for not working this problem. Question number 10. Your answer was A. Correct. This is a written question, worth 17 points. DO NOT place the problem code on the answer sheet. A proctor will fill this out after exam submission. Show all steps (work) on your answer sheet for full credit. Problem Code: 1015 The following data indicates the number of hours that Johnny spent studying the week before each exam in his classes along with the corresponding exam scores: hours studying 3 7 9 11 15 18 score on exam 53 48 59 71 80 93 Part a: Identify the explanatory and response variables for this situation. Part b: Create a scatterplot of the data. Part c: Give the LSRL equation for this data. Part d: Find the correlation coefficient and the coefficient of determination for this data. What do each of these tell you about the relationship between the variables? Based on this information,
do you think your answer in part c is a good model? Part e: Find the residual value corresponding to the explanatory variable value of 9. A I have placed my work and my answer on my answer sheet. B I want to have points deducted from my test for not working this problem.
