Basic Statistics - Old Questions

11. The fuel consumption of a new model of cars is being tested. In one trial, 50 cars chosen at random were driven under identical conditions, and the distances, x km, covered on 1 liter of petrol were recorded. The results gave the following totals: Σx = 525, Σx² = 5625. Calculate the 99% confidence interval for the mean petrol consumption, in km per liter. Interpret the result. [5]