MATH 533 Final Exam (Example 3)




MATH 533 Final Exam (Example 3)

The length of time to do a cable installation by Multi-Cable Inc. is normally distributed with a mean of 42.8 minutes and a standard deviation of 6.2 minutes.  What percentage of installations take less than 30 minutes?

2.     Accident claims are checked for completeness by branch offices of Fortune Insurance before they are sent to a regional office for payment.  Historically 80% of the claims are complete when they reach the regional office.  You select a random sample of 20 claims that have arrived at the regional office.  Find the probability that:……..
3.     Until this year the mean braking distance of a Nikton automobile moving at 60 miles per hour was 175 feet.  Nikton engineers have developed what they consider a better braking system.  They test the new brake system on a random sample of 81 cars and determine the sample mean braking distance.  The results are:…….
4.     The manager at Trion Electric Co-op is concerned about the rise in the number of late payments.  If more than 10% of the accounts are behind in their payments, the manager will initiate a costly monitoring program.  A random sample of 75 accounts shows that 9 were behind in their payments.
5.     A manufacturer of athletic footwear claims that the mean life of his product will exceed 50 hours.  A random sample of 36 pairs of shoes leads to the following results in terms of useful life:……
6.     AJ AUCTION sells art drawings of little known artist at auction. The dealer is interested in the relationship between the final sale price ($) (Y) and the number of persons bidding on the drawing (X).  A random sample of 20 drawing is selected…….
7.     The personnel department  of a large industrial corporation would like to develop a model to predict the weekly salary based upon the length of employment and age of its managerial employees. Salary is modeled as a linear function of length of employment and age……..