Question

A jar manufacturer is very concerned about the consistency of the diameters of jars produced by his machines and believes that the jars produced by machine "A" have a different variance in diameter than the variance in diameter from machine "B". A sample of 10 jars from machine "A" has the sample variance of 0.0396. A sample of 21 jars from machine "B" has the sample variance of 0.0231. Construct the 95% confidence interval for the ratio of the population variances. Round your answers to four decimal places.

Answer 1

For 95% confidence interval the critical values are = 2.8365

                                                                               = 0.2727

The 95% confidence interval for ratio of population variances are

= (0.0396/0.0231) * (1/2.8365) < < (0.0396/0.0231) * (1/0.2727)

= 0.6044 < < 6.2863