Fuel Consumption and Cars
One measure of a vehicle's front-end alignment is the caster angle-the relationship between the upper and lower ball joints. The specifications for a certain sports car include a caster angle of 2.8° with variance 0.40. Twenty-two new sports cars were randomly selected, and the caster angle was measured for each. The sample variance was 0.55.
a. Find a 95% confidence interval for the population variance in caster angle. Assume normality.
b. Is there any evidence to suggest the population variance in caster angle is different from 0.40? Justify your answer.