A new material is being tested for use in the manufacture of electrical conduit, to

Chapter 6, Problem 4

(choose chapter or problem)

Exercises 1 to 4 describe experiments that require a hypothesis test. For each experiment, describe the appropriate test. State the appropriate null and alternate hypotheses, describe the test statistic, and specify which table should be used to find the P-value. If relevant, state the number of degrees of freedom for the test statistic.

A new material is being tested for use in the manufacture of electrical conduit, to determine whether it will reduce the variance in crushing strength over the old material. Crushing strengths are measured for a sample of size 16 of the old material and a sample of size 20 of the new material. If it is shown that the crushing