(a)[6]
Calculate a 96% confidence interval for the population mean length of the lectures.
(b)[1]
Because the sample size was large, the method used in part (a) is valid. Explain why it would not remain valid if the sample size were small.
Mathematics 9709 · AS & A Level · Sampling and estimation
Sampling and estimation — practice question
A student records the duration, $t$ minutes, of a number of lectures. The results from a random sample of 80 lectures are summarised below. $n = 80$, $\sum t = 6430$, $\sum t^2 = 519\,740$.
Worked solution & mark scheme
This 7-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Sample mean estimate: $\hat{\mu}=\frac{6430}{80}=\frac{643}{8}=80.375$” …
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