Refer to the Trends in Biomaterials & Artificial Organs (January 2003) study of a new bonding adhesive for teeth called "Smartbond," presented in Exercise. Recall that tests on a sample of 10 extracted teeth bonded with the new adhesive resulted in a mean breaking strength (after 24 hours) of x = 5.07 Mpa and a standard deviation of s = .46 Mpa. In addition to requiring a good mean breaking strength, orthodontists are concerned about the variability in breaking strength of the new bonding adhesive.

a. Set up the null and alternative hypothesis for a test to determine whether the breaking strength variance differs from .5 Mpa.

b. Find the rejection region for the test, using α = .01.

c. Compute the test statistic.

d. Give the appropriate conclusion for the test.

e. What conditions are required for the test results to be valid?