Quiz 4 SU3
Math 131 Name:
Quiz 4 (Chapter 5) Total Points: 20 â€¨
INSTRUCTIONS: Show all your work and good luck. Use the Genius Scan app to scan your completed quiz,
then submit the pdf under the Assignments tab in Canvas by 11:59pm on Thursday, July 30th. Round all
solutions to the hundredths place. Write down all computations you have a calculator perform.
1. Suppose Professor Poinsettâ€™s commute times to the Freehold campus distribute approximately normally
Â Â Â Â Â with a mean time of 51 minutes and a standard deviation of 6.3 minutes.
a. Draw an accurate sketch of the distribution of commute times. Be sure to Â Â Â Â Â Â Â Â
Â Â Â Â Â Â Â Â Â Â label the mean, as well as the points one and two standard deviations away
Â Â Â Â Â Â Â Â Â Â from the mean. (3pts)â€¨
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b. On a randomly chosen work day, whatâ€™s the likelihood he made it in less than 50 minutes? (3pts)â€¨
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c. In a sample of 25 randomly chosen workdays, whatâ€™s the likelihood Professor Poinsett made it to work
Â Â Â Â Â Â Â Â Â in less than 50 minutes on average? (3pts)â€¨
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d. Which probability in parts b. and c. above is smaller and why? (2pts)â€¨
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e. On a randomly chosen work day, whatâ€™s the likelihood he made it in more than an hour? (3pts)â€¨
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f. On a randomly chosen work day, whatâ€™s the chance he made it between 45 and 55 minutes? (3pts)â€¨
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g. Suppose Professor Poinsett loses his cool in the top 2% of commute times. At what drive time does
Â Â Â Â Â Â Â Â Â Â he start to lose his cool? I suggest drawing a graph. (3pts)
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