(a)[2]
The mean of these 40 values is $124.0$; determine $k$.
(b)[2]
Determine the standard deviation of these 40 values of $x$.
Mathematics 9709 · AS & A Level · Representation of data
Representation of data — practice question
For 40 values of $x$, it is given that $\Sigma(x - k) = 836.0$ and $\Sigma(x - k)^2 = 25410.8$, 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: “Set up a correct equation by equating the total to the mean, e.g. $4960-40k=836$ or $124-k=20.9$.” …
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