Question

The time required to finish a test in normally distributed with a mean of 80 minutes and a standard deviation of 15 minutes what is the probability That a student chosen at random will finish the test in more than 110 minutes

Answer 1

Let the time taken to f,inish the test be x.
P(x > 110) = 1 - P(x < 110) = 1 - P(z < (110 - 80)/15) = 1 - P(z < 2) = 1 - 0.9773 = 0.0227