Mathematics 9709 · AS & A Level · Sampling and estimation
Sampling and estimation — practice question
The table below summarises the amounts spent by $160$ shoppers at a supermarket: amount spent $(\$x)$ in the classes $0<x\leq30$, $30<x\leq50$, $50<x\leq70$, $70<x\leq90$, $90<x\leq140$ and the matching numbers of shoppers $16, 40, 48, 26, 30$.
(i)[4]
Plot a cumulative frequency graph for this distribution.
(ii)[3]
Estimate the median and interquartile range of the amount spent.
(iii)[2]
Estimate how many shoppers spent more than $\$115$.
(iv)[2]
Calculate an estimate for the mean amount spent.
Worked solution & mark scheme
This 11-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Cumulative frequency values formed correctly” …