Quiz 4 SU3
Math 131 Name:
Quiz 4 (Chapter 5) Total Points: 20 

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 Poinsett’s commute times to the Freehold campus distribute approximately normally
     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
          label the mean, as well as the points one and two standard deviations away
          from the mean. (3pts)



b. On a randomly chosen work day, what’s the likelihood he made it in less than 50 minutes? (3pts)

     

















c. In a sample of 25 randomly chosen workdays, what’s the likelihood Professor Poinsett made it to work
         in less than 50 minutes on average? (3pts)



















d. Which probability in parts b. and c. above is smaller and why? (2pts)

















Page of 1 2


e. On a randomly chosen work day, what’s the likelihood he made it in more than an hour? (3pts)

































f. On a randomly chosen work day, what’s the chance he made it between 45 and 55 minutes? (3pts)



































g. Suppose Professor Poinsett loses his cool in the top 2% of commute times. At what drive time does
          he start to lose his cool? I suggest drawing a graph. (3pts)








Page of 2 2