(i)[1]
Calculate $\Sigma(x - 62)$.
(ii)[1]
Calculate $\Sigma(x - 62)^2$.
(iii)[3]
Determine the mean and variance of the speeds of the 8 cars.
Mathematics 9709 · AS & A Level · Sampling and estimation
Sampling and estimation — practice question
A traffic camera recorded the speeds, $x$ kilometres per hour, of 8 cars moving along one street and obtained these results: $62.7,\;59.6,\;64.2,\;61.5,\;68.3,\;66.9,\;62.0,\;62.3$.