An experiment reported in Popular Science compared fuel economies for two types of similarly equipped diesel mini trucks. Let us
suppose that 11 Volkswagen and 9 Toyota trucks were tested in 90- kilometers per-hour steady-paced trials. If the 11 Volkswagen trucks averaged 16 kilometers per liter with a standard deviation of 1.0 kilometer per liter and the 9 Toyota trucks averaged 11 kilometers per liter with a standard deviation of 0.8 kilometer per liter. Assume that the distances per liter for the truck models are approximately normally distributed with equal variances. Construct a 98% confidence interval for ????????1/????????2, where ????????1 and ????????2 are, respectively, the standard deviations for the distances traveled per liter of fuel by the Volkswagen and Toyota mini trucks.
