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Calculate the numerical value of $\sum h^2$.
Mathematics 9709 · AS & A Level · Sampling and estimation
Sampling and estimation — practice question
The height of a plant from a particular species is represented by $H$ cm. Heights were measured for a random sample of $100$ plants, and the following were obtained.
• The sample mean, $\bar{h}$, was $80.2$.
• An unbiased estimate of the population variance of $H$ was $15.6$.
Worked solution & mark scheme
This 3-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Using the unbiased (or biased) variance formula to obtain $15.6=\frac{100}{99}\left(\frac{\sum h^2}{100}-80.2^2\right)$ or equivalent” …
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