Alawyer commutes daily from his suburban home to his midtown office. the average time for a one-way trip is 24 minutes, with a standard deviation of 3.8 minutes. assume the distribution of the trip-length to be normally distributed. during a period of 20 work days, on how many days should you expect the lawyer to be late for work?

lawyer will be late for at least 17 days

Explanation:

given,

average time for a one way trip = 24 minutes

standard deviation = 3.8 minute

P(of late) = P(x>20 min)

 =

= 0.5 + 0.3531

= 0.8531 = 85.31 %                    

days lawyer would be late for work

 = n p = 20 × 0.8531 = 17.062 days

hence, lawyer will be late for at least 17 days during a period of 20 work day.

51% were unhappy, i think .   ; )