(a)[2]
Using the fact that the mean of these 40 values of $x$ is $34$, determine the value of $k$.
(b)[2]
Find the variance for these 40 values of $x$.
Mathematics 9709 · AS & A Level · Representation of data
Representation of data — practice question
For 40 values of $x$, the following totals are given: $\sum (x - k) = 520$, $\sum (x - k)^2 = 9640$, with $k$ a constant.
Worked solution & mark scheme
This 4-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Sets up the correct equation for the mean, for example $\frac{\sum x}{40}-k=\frac{\sum(x-k)}{40}$.” …
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