Suppose that the distribution of keyboarding speeds for students who have completed a two- week keyboarding course is approximately normal with a mean of 82 words per minute (wpm) and standard deviation of 9 wpm. In the questions below, assume that a student has been randomly selected from the population of students who have completed the keyboarding course.
(a) What is the probability that a randomly selected student's keyboarding rate is at most 100 words per minute?
(b) What is the probability that a randomly selected student's rate is between 70 and 90 wpm?
(c) Suppose that additional training will be made available to the slowest 20% of students who completed the keyboarding class. What keyboarding speeds would qualify for the training?