The travel time for a college student traveling between her home and her college is uniformly distributed between 40 and 90 minutes.The probability that her trip will take longer than 60 minutes is
A) 1.00
B) 0.40
C) 0.02
D) 0.60

Question

Quizplus · Accepted Answer

Since the travel time is uniformly distributed between 40 and 90 minutes, the total area under the curve equals 1. The probability that her trip will take longer than 60 minutes can be found by calculating the area under the curve to the right of 60 minutes. 
The length of the total interval is 90 - 40 = 50 minutes. Since the distribution is uniform, the probability density function is a flat line with height 1/50. The area of a rectangle with height 1/50 and width (90 - 60) = 30 minutes is (1/50) * 30 = 0.6.
Therefore, the probability that her trip will take longer than 60 minutes is 0.6 or 60%.

The Travel Time for a College Student Traveling Between Her