PLUSLine is a 24-hour PLUS toll free customer care line. The highway users can receive the latest traffic updates, lodge a feed, or request for PLUSRonda assistance on the PLUS expressways. The following are the average duration per call (in minutes) received in a day, for the previous two months, from motorists for roadside service:

26 14 18 9 21 23 17 10 24 17 7 11 15 17 13 16 22 14 23 18 25 8 21 5 12 15 19 20 21 11 27 16 12 19 20 25 24 6 15 23 14 18 13 27 23 14 17 29 14 13 23 17 18 10 9 4 19 13 6 17 12

a. Develop a frequency distribution for the average duration per call in a day. Discuss what the most concentration of the distribution tells you about the sample data.

b. Based on the results in part

a, construct a frequency histogram for the sample data.