A shopkeeper goes to a clothes fair. He records the costs of jeans. The costs are shown in the table. Cost of jeans (E's) Frequency Cumulative frequency 10-15 11 16-20 35 21-25 34 26-30 16 31-35 10 36-40 5 a Complete the cumulative frequency table. b Calculate Pa c Calculate Po d Calculate the 20% to 80% interpercentile range.

AppendixLO1