Chapter 11, Problem 6CR

Before you solve Problems 6-10, first classify the problem as one of the following:

Chi-square test of independence or homogeneity

Chi-square goodness of fit

Chi-square for testing ${\sigma }^2\text{ or }\sigma$

Then in each of the problems when a test is to be performed do the following:

(i) Give the value of the level of significance. State the null and alternate hypotheses.

(ii) Find the sample test statistic.

(iii) Find or estimate the P-value of the sample test statistic.

(iv) Conclude the test.

(v) Interpret the conclusion in the context of the application.

Packaging: Corn Flakes A machine that puts corn flakes into boxes is adjusted to put an average of 15 ounces into each box, with standard deviation of 0.25 ounce. If a random sample of 12 boxes gave a sample standard deviation of 0.38 ounce, do these data support the claim that the variance has increased and the machine needs to be brought back into adjustment? Use a 0.01 level of significance. Assume volume in boxes is normally distributed.