The owner of a petrol station wants to study fuel-purchasing habits of motorists at his station. A random sample of 60 motorists during a particular week gave the following results:

Amount purchased: = 42.8 litres, S =10.3 litres.

9 motorists purchased diesel.

(a)State, in words and in symbols, the hypotheses to be tested.

(b)What is the p-value?

(c)Is there evidence to reject the null hypothesis? Justify your answer.

(d)State the conclusion in context.