The fuel consumption of a certain make of car may not be exactly that rated by the manufacturer. Suppose ten cars of the same model were tested for combined city and highway fuel consumption, with the following results:
(a) Estimate the sample mean and sample standard deviation of the actual fuel consumption of this particular model of car.
(b) Suppose that the manufacturer's stated fuel consumption of this particular model of car is 7 litres per 100km; perform a hypothesis test to verify the stated fuel consumption with a significance level of 2%.