A machine produces pipes used in airplanes. The average length of the pipe is 16 inches. The acceptable variance for the length is .3 inches. A sample of 25 pipes was taken. The average length in the sample was 15.95 inches with a variance of .4 inches.
a. Construct a 95% confidence interval for the population variance.
b. Construct a 95% confidence interval for the population standard deviation.
c. Test at the 5% level of significance that whether the variance of length of pipes is significantly different from the standards.
Please make sure these are included as part of the problem
A. State the null and alternative hypotheses to be tested.
B.. Compute the test statistic.
C.. State the decision rule
D.. Draw conclusions.