Question

A large company is interested in improving the efficiency of its customer service and decides to examine the length of the business phone calls made to clients by its sales staff. Here is a cumulative relative frequency graph from data collected over the past year. According to the graph, the shortest 80% of calls will take how long to complete?

a. Less than 10 minutes

b. At least 10 minutes

c. Exactly 10 minutes

d. At least 5.5 minutes

e. Less than 5.5 minutes

Section II: Free Response Show all your work. Indicate clearly the methods you use, because you will be graded on the correctness of your methods as well as on the accuracy and completeness of your results and explanations.

Short answer

According to the graph, the shortest 80% of calls will take less than 10 minutes to complete.

Step-by-step solution

Given information

The graph is ,

Explanation for the correct option

Draw a line to the right of $80$percent on the Y-axis until it reaches the blue graph. As a result, it is cumulative; the entire left side would take less than 10 minutes. Because the value is ten minutes, the call's shortest $80$percent duration will be less than ten minutes.

As a result, the best solution is (a)

Explanation for the incorrect option

(b) According to the graph, the shortest 80% of calls will not take at least 10 minutes long to complete.

(c)According to the graph, the shortest 80% of calls will not take exactly 10 minutes long to complete.

(d)According to the graph, the shortest 80% of calls will not take at least 5.5 minutes long to complete.

(e) According to the graph, the shortest 80% of calls will not take less than 5.5 minutes long to complete.