1. The following table gives the frequency distribution of the number of hours each

group of people out of 40 took to finish the same amount of work. [10 Marks]

Number of hours

4-6

7-9

10 - 12

13-15

16 - 18

fi

5

7

12

10

6

n = 40

a) Find the mode, median and mean

b) Find the range, variance and standard deviation