(a)[4]
Calculate a mean estimate.
(b)[2]
Fill in the cumulative frequency table below.
(c)[3]
On the grid, sketch the cumulative frequency diagram.
(d(i))[1]
Use your cumulative frequency diagram to estimate the median.
(d(ii))[2]
Use your cumulative frequency diagram to estimate the interquartile range.
(d(iii))[2]
Use your cumulative frequency diagram to estimate how many students spent more than $25$.