The distribution of the lifetimes of torch batteries is shown in the grouped frequency table below. Lifetime Frequency Cumulative frequency (nearest 0.1 of an hour) 5.0-5.9 5 6.0-6.9 8 7.0-7.9 10 8.0-8.9 22 9.0-9.9 10 10.0-10.9 2 a Complete the cumulative frequency column. b Write down the class boundaries for the second group. c Work out the mid-point of the fifth group.

AppendixLO1