(a(i)(a))[1]
Estimate the median height from the diagram.
(a(i)(b))[2]
Estimate the $30$th percentile from the diagram.
(a(ii))[2]
Heights above $y$ m are put into Class I. $\frac{2}{5}$ of the $80$ trees are in Class I. Find $y$.
(a(iii))[2]
Finish the frequency table for the heights of the Variety $A$ trees.
(b)[6]
With midpoints, the estimated mean height of Variety $B$ trees is $1.81$ m. Calculate $p$ and $q$.