The manager of a fast-food restaurant determines that the average time that her customers wait for service is 2 minutes. Find the probability that a customer is served within the first 2 minutes. Select the correct answer.
A) $\quad 1.6321$
B) $\quad 0.6321$
C) $4.6321$
D) $\quad 3.6321$
E) $2.6321$

Question

Quizplus · Accepted Answer

Since the average time that customers wait for service is 2 minutes, we can assume that the waiting time follows a normal distribution with a mean of 2 minutes. To find the probability that a customer is served within the first 2 minutes, we need to find the area under the normal curve to the left of 2 minutes. Using a standard normal table or calculator, we can find that the z-score corresponding to 2 minutes is 0. Plugging this into the standard normal cdf function, we get P(Z < 0) = 0.5 - 0.5(0) = 0.5. Therefore, the probability that a customer is served within the first 2 minutes is 0.5 or 50%. The correct answer is B.

The Manager of a Fast-Food Restaurant Determines That the Average 1.6321\quad 1.63211.6321

The Manager of a Fast-Food Restaurant Determines That the Average $\quad 1.6321$