The time required to complete the final examination in particular college course is normally distributed with mean of 80 minutes and standard deviation of 10 minutes. Reply the following questions.
a) Determine the probability of completing the exam in one hour or less?
b) Determine the probability that a student will complete the exam in more than 60 minutes but less than 75 minutes?
c) Suppose that class has 60 students and that examination period is 90 minutes in length. How many students do you expect will be unable to complete exam in assigned time?