THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION:
The amount of time you have to wait at a particular stoplight is uniformly distributed between zero and two minutes.
-What is the probability that you have to wait between 15 and 45 seconds for the stoplight?
A)0.15
B)0.25
C)0.35
D)0.45

Question

Quizplus · Accepted Answer

We need to convert the waiting time for the stoplight to seconds, so the range is from 0 seconds to 120 seconds. The probability of waiting between 15 and 45 seconds is the same as waiting between 0.25 and 0.75 minutes. So, the probability can be found by taking the difference between the cumulative probability of 0.75 and 0.25, which is 0.5. Therefore, the probability is 0.5/2 = 0.25. Hence, the best answer choice is (B).