Chapter 12 QUIZ

TRUE OR FALSE

Question 12.160

1. True or false: The curve is symmetric.

Question 12.161

2. True or false: The total area under the curve equals 1.

Question 12.162

3. True or false: If we reject the null hypothesis in an ANOVA, we conclude that there is evidence that all the population means are different.

FILL IN THE BLANK

Question 12.163

4. A weighted average (mean) of quantities that are squared is called a ________ ________ [two words].

Question 12.164

5. The ________ ________ ________ [three words] measures the variability in the sample means.

Question 12.165

6. The ________ ________ ________ [three words] measures the variability within the samples.

SHORT ANSWER

Question 12.166

7. What do we use for an estimate of the overall population mean?

Question 12.167

8. In the ANOVA table, what is the relationship between the quantities in the mean square column with respect to the quantities in the sum of squares column and the degrees of freedom column?

Question 12.168

9. For analysis of variance, the -value represents the area to the right of what?

CALCULATIONS AND INTERPRETATIONS

For Exercises 10–12, assume that the requirements for ANOVA have been met and test, using level of significance , whether the population means are equal.

Question 12.169

10. Gas Mileage and Number of Cylinders. When it comes to getting good gas mileage, does the number of cylinders in your engine make a difference? The following table provides the summary statistics regarding miles per gallon for 4-cylinder, 6-cylinder, and 8-cylinder cars.

4 cylinders 6 cylinders 8 cylinders
199 83 103
29.3 20.0 15.0
5.7 3.8 2.9

713

Question 12.170

11. Hours Worked and Marital Status. The General Social Survey tracks demographic trends. Here, we are interested in whether the mean number of hours worked differs by marital status. The summary statistics are shown here.

image

Question 12.171

12. Calories in Breakfast Cereals. A dietary researcher is interested in whether differences exist in the mean number of calories in breakfast cereals made by different manufacturers. The summary statistics for the samples from three manufacturers appear in the following table.

Kellogg's quaker Ralston purina
23 8 8
109 95 115
22 29 23