A comparison of the precisions of two machines developed for extracting juice from oranges is to be made using the following data.

Machine A

s²=49.5g²

n=21

Machine B

s²=33.5g²

n=21

(a) Is there sufficient evidence to indicate that there is a difference in the precision of the two machines at the 5% level of significance? (Round your answers to two decimal places.)

Test statistic:F=

Rejection region:F>

b) Find a 95% confidence interval for the ratio of the two population variances. (Round your answers to two decimal places.)