The owner of a company wanted to understand the length of phone call conversations between the company's employees and their customers. The owner took a random sample of phone calls and recorded the length, (minutes), then summarised these in the following frequency table:

class(minutes) frequency

(0,20) 68

(20,40) 75

(40,60) 30

(60,80) 27

total 200

a)How many phone calls lasted longer than 40 minutes and less than or equal to 60 minutes?

b) Calculate the cumulative relative frequency, as a percentage, for the (40, 60] class. SHOW BASIC WORKINGS.

c) Please interpret your answer to part b), in the context of this question.