(a)[3]
Find unbiased estimates for the population mean and variance.
(b)[1]
State one statistical reason why these estimates may not be reliable.
Mathematics 9709 · AS & A Level · Sampling and estimation
Sampling and estimation — practice question
A random sample of 12 rods from a particular machine has lengths, in millimetres, given by $200,\;201,\;198,\;202,\;200,\;199,\;199,\;201,\;197,\;202,\;200,\;199$.
Worked solution & mark scheme
This 4-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Mean estimate $\mathrm{est}(\mu)$ given as $\frac{1199}{6}$ or $199.833$ or $200$ or $\frac{2398}{12}$” …
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