The waiting time at an elevator is uniformly distributed between 30 and 200 seconds. What is the probability a rider must wait more than 1.5 minutes?
A) 0.3529
B) 0.4500
C) 0.5294
D) 0.6471

Question

Quizplus · Accepted Answer

1.5 minutes is 90 seconds. The probability of waiting more than 90 seconds is the area from 90 to 200 over the total area from 30 to 200. This is (200-90)/(200-30) = 110/170 = 0.6471.

The Waiting Time at an Elevator Is Uniformly Distributed Between