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 here models the distribution of Y, the amount of time after class ends (in minutes) when Mr. Shrager dismisses the class on a randomly selected day. (A negative value indicates he ended class early.)

a. Find and interpret P(−1 ≤ Y ≤ 1).

b. What is μY ? Explain your answer.

c. Find the value of k that makes this statement true: P(Y ≥ k) = 0.25.

-1 4 Y = Dismissal time (min. after class ends)