Refer to Examples 13.2 and 13.3.a Use the portion of the

Chapter 13, Problem 20E

(choose chapter or problem)

Problem 20E

Refer to Examples 13.2 and 13.3.

a Use the portion of the data in Table 13.2 that deals only with teaching technique 1 and the method of Section 8.8 to form a 95% confidence interval for the mean score of students taught using technique 1.

b How does the length of the 95% confidence interval that you found in part (a) compare to the length of the 95% confidence interval obtained in Example 13.3?

c What is the major reason that the interval that you found in part (a) is longer than the interval given in Example 13.3?

Reference

Refer to Exercises 8.90 and 10.77.

a Use an F test to determine whether there is sufficient evidence to claim a difference in the mean verbal SAT scores for high school students who intend to major in engineering and language/literature. Give bounds for the associated p-value. What would you conclude at the α= .05 level of significance?

b Applet Exercise Use the applet F-Ratio Probabilities and Quantiles to determine the exact p-value for the test in part (a).

c How does the value of the F statistic obtained in part (a) compare to the value of the t statistic that you obtained in Exercise 10.77?

d What assumptions are necessary for the analyses performed in part (a)?

State the assumptions underlying the ANOVA of a completely randomized design.