Question

an online customer service department estimates that about 15 percent of callers have to wait more than 8 minutes to have their calls answered by a person. the department conducted a simulation of 1,000 trials to estimate the probabilities that a certain number of callers out of the next 10 callers will have to wait more than 8 minutes to have their calls answered. the simulation is shown in the following histogram. based on the simulation, what is the probability that at most 2 of the next 10 callers will have to wait more than 8 minutes to have their calls answered? a 0.150 b 0.190 c 0.474 d 0.526 e 0.810

Explanation:

Step1: Understand the meaning of "at most 2"

"At most 2" means the number of callers is 0, 1, or 2.

Step2: Sum the relative frequencies

We need to sum the relative frequencies for 0, 1, and 2 callers.
The relative frequency for 0 callers is \(0.181\), for 1 caller is \(0.345\), and for 2 callers is \(0.284\).

$$0.181 + 0.345+0.284$$

$$=0.810$$

Answer:

E. 0.810