Mr. Shrager does not always let his statistics class out on time. In fact, he seems to end class according to his own “internal clock.” The density curve models the distribution of the amount of time after class ends (in minutes) when Mr. Shrager dismisses the class. (A negative value indicates he ended class early.)

a. What height must the density curve have? Justify your answer.

b. About what proportion of the time does Mr. Shrager dismiss class within 1 minute of its scheduled end time?

c. Calculate and interpret the 20th percentile of the distribution.

-1 4 Dismissal time (minutes after class ends)