A roadside assistance firm kept a record over a week of the amount of time, in minutes, people were kept waiting for assistance in a particular part of the country. The time taken was from the time the phone call was received to the arrival of the breakdown mechanic. The times are shown below. Time Waiting (minutes) 20-30 30-40 40-50 Frequency 50-60 60-70 6 10 18 13 2 a Work out the number of people who called for assistance. b Calculate the 30th percentile. e Calculate the 65th percentile.

AppendixLO1