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State the value of $n$.
Mathematics 9709 · AS & A Level · Sampling and estimation
Sampling and estimation — practice question
Andy records the number of emails, $x$, that he gets each day and observes that, over $n$ days, $\sum(x - 10) = 27$ and the mean number of emails is $11.5$.
Worked solution & mark scheme
This 3-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Construct a three-term equation that includes $27$ and at least one term in $n$ with no $x$ present, e.g. $11.5n = 27 + 10n$ or $11.5 = \frac{27}{n} + 10$” …
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