(i)[2]
Calculate the frequencies shown by the four histogram bars.
(ii)[4]
On the grid on the next page, draw a cumulative frequency graph for the lengths of worms in the garden.
(iii)[3]
Use your graph to estimate the median and the interquartile range for the lengths of worms in the garden.
(iv)[2]
Calculate an estimated mean length for the worms in the garden.