Statistics Chapter 11 Exam Questions with Verified Solutions Rated 100%

Statistics Chapter 11 Exam Questions with Verified Solutions Rated 100% The degrees of freedom for error is called ______. a. degrees of freedom error b. degrees of freedom denominator c. degrees of freedom within-groups d. all of these - Answers d. all of these A researcher compares differences in positivity between participants in a low-, middle-, or upper middle-class family. If she observes 15 participants in each group, then what are the degrees of freedom for the one-way between-subjects ANOVA? a. (2, 42) b. (3, 12) c. (2, 12) d. (3, 43) - Answers a. (2, 42) A researcher observed the mating behavior of 10 porpoises in 5 different social conditions. What are the degrees of freedom between-groups for a one-way within-subjects ANOVA? a. There is not enough information to answer this question. b. 4 c. 9 d. 27 - Answers b. 4 Computing a one-way within-subjects ANOVA is appropriate when ______. a. different participants are assigned to each group b. the same participants are observed across groups c. the levels of one or more independent variables are manipulated d. all of these - Answers b. the same participants are observed across groups A researcher conducts a study using the one-way between-subjects ANOVA. He computes = 120 and = 200. What is the effect size for this test using eta-squared? a. .38 b. There is not enough information to answer this question. c. 1.67 d. .60 - Answers a. .38 Using a between-subjects ANOVA design, ______. a. the same participants are observed in each group b. data are not analyzed between groups c. n participants are observed k times d. n · k participants are each observed one time - Answers d. n · k participants are each observed one time Post hoc tests are computed ______. a. following a significant ANOVA test to make pairwise comparisons b. to determine which set of degrees of freedom can be attributed to the variability between-groups c. to determine if groups means differ, even for tests in which the decision is to retain the null hypothesis d. prior to conducting a hypothesis test - Answers a. following a significant ANOVA test to make pairwise comparisons Which of the following is a measure of proportion of variance for a one-way between-subjects ANOVA? a. omega-squared b. both A and B c. eta-squared d. estimated Cohen's d - Answers b. both A and B The following result is reported for a one-way within-subjects ANOVA: F(2, 27) = 3.20, p < .05 ( = .14). Which value in the summary suggests that the design was within-subjects? a. the test statistic value b. the p value c. the partial estimate for eta-squared d. the degrees of freedom - Answers c. the partial estimate for eta-squared The following is a summary of a one-way between-subjects ANOVA: F(2, 37) = 3.42, p < .05, = .12. How many pairwise comparisons need to be made for this ANOVA result? a. 12 b. 2 c. 4 d. 3 - Answers d. 3 In a study with 4 groups and 10 participants in each group, the sum of squares for the between-groups source of variation is 60. What is the value for the mean square between-groups in this study? a. 10 b. 20 c. 1.67 d. 15 - Answers b. 20 Which of the following is an assumption for computing a one-way within-subjects ANOVA? a. The population being sampled from is positively skewed. b. Different participants were observed in each group. c. Independent observations were made within groups, but not between groups. d. all of these - Answers c. Independent observations were made within groups, but not between groups. A researcher conducts a study in which k = 5 and N = 80. What are the degrees of freedom between-groups for the one-way between-subjects ANOVA? a. 5 b. 75 c. 395 d. 4 - Answers d. 4 A researcher conducts two studies using the one-way between-subjects ANOVA. The sum of squares between groups is larger in Study 1 than in Study 2; the sum of squares total is smaller in Study 1 than in Study 2. Using eta-squared, in which study will the effect size be larger? a. There is not enough information to answer this question. b. Study 1 c. Study 2 - Answers b. Study 1 Which source of variation is computed using a one-way within-subjects ANOVA, but not a one-way between-subjects ANOVA? a. within-groups variation b. between-persons variation c. between-groups variation