Mathematics 9709 · AS & A Level · Hypothesis testing
Hypothesis testing — practice question
In the previous year, the average pizza-delivery time from Pete’s Pizza Pit was $32.4$ minutes. This year, the delivery time, $t$ minutes, from Pete’s Pizza Pit was noted for a random sample of $50$ deliveries. The results were:
$n = 50 \qquad \sum t = 1700 \qquad \sum t^2 = 59\,050$
(a)[3]
Determine unbiased estimates of the population mean and variance.
(b)[5]
Test, at the $2\%$ significance level, whether the mean delivery time has altered since last year.
(c)[1]
In answering (b), in what situation would the Central Limit Theorem not need to be used?
Worked solution & mark scheme
This 9-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Sample mean correctly found $\bar{x} = \frac{1700}{50} = 34$” …