(i)[2]
Find how many children are in the group.
(ii)[3]
Find the value of $\Sigma(x - 104.8)^2$.
Mathematics 9709 · AS & A Level · Sampling and estimation
Sampling and estimation — practice question
The heights, $x$ cm, of a set of young children are summarised by $\Sigma(x - 100) = 72$, $\Sigma(x - 100)^2 = 499.2$. The mean height is $104.8$ cm.
Worked solution & mark scheme
This 5-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Forms equation $\frac{72}{n}+100=104.8$ or $72+100n=104.8n$.” …
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