CHAPTER 10 #2.A researcher is interested in whether studying with music helps or hinders the learner. To control for differences in cognitive ability, the researcher decides to use a within-subjects design. He selects a random sample of participants and has them study different material of equal difficulty in both the music and no music conditions. Next, the students take a 20item quiz on the material. The study is completely counterbalanced to control for order effects. The data appear next. They are measured on an interval-ratio scale and are normally distributed. Music No Music 17 17 16 18 15 17 16 17 18 19 18 18 a.What statistical test should be used to analyze these data? b.Identify H0 and Ha for this study. c.Conduct the appropriate analysis. d.Should H0 be rejected? What should the researcher conclude? e.If significant, draw a graph representing the data. f.Calculate the 95% confidence interval. #4. You notice at the gym that it appears that more women tend to work out together, whereas more men tend to work out alone. To determine whether this difference is significant, you collect data on the workout preferences for a sample of men and women at your gym. The data follow. Males Females Together 12 24 Alone 22 10 a.What statistical test should be used to analyze these data? b.Identify H0 and Ha for this study. c.Conduct the appropriate analysis. d.Should H0 be rejected? What should the researcher conclude? You notice at the gym that it appears that more women tend to work out together, whereas more men tend to work out alone. To determine whether this difference is significant, you collect data on the workout preferences for a sample of men and women at your gym. The data follow. Males Females Together 12 24 Alone 22 10 a.What statistical test should be used to analyze these data? b.Identify H0 and Ha for this study. c.Conduct the appropriate analysis. d.Should H0 be rejected? What should the researcher conclude? CHAPTER 11 #10 You notice at the gym that it appears that more women tend to work out together, whereas more men tend to work out alone. To determine whether this difference is significant, you collect data on the workout preferences for a sample of men and women at your gym. The data follow. Males Females Together 12 24 Alone 22 10 a.What statistical test should be used to analyze these data? b.Identify H0 and Ha for this study. c.Conduct the appropriate analysis. d.Should H0 be rejected? What should the researcher conclude? A researcher conducted an experiment on the effects of a new \"drug\" on depression. The researcher had a control group that received nothing, a placebo group, and an experimental group that received the \"drug.\" A depression inventory that provided a measure of depression on a 50-point scale was used (50 indicates that an individual is very high on the depression variable). The ANOVA summary table appears next, along with the mean depression score for each condition. #12 Source df SS MS Between groups 1,202.313 Within groups 2,118.00 Total 3,320.313 \"Drug\" Condition Mean n Control 36.26 15 Placebo 33.33 15 \"Drug\" 24.13 15 a.Complete the ANOVA summary table. b.Is Fobt significant at = .05; at = .01? c.Perform post hoc comparisons if necessary. d.What conclusions can be drawn from the F-ratio and the post hoc comparisons? e.What is the effect size, and what does this mean? f.Graph the means. #12. A researcher has been hired by a pizzeria to determine which type of crust customers prefer. The restaurant offers three types of crust: hand-tossed, thick, and thin. Following are the mean number of 1-inch pieces of pizza eaten for each condition from 10 subjects who had the opportunity to eat as many pieces with each type of crust as they desired. The ANOVA summary table also follows. Source df SS MS Subject 2.75 Between 180.05 Error 21.65 Total 204.45 Crust Type Mean n Handtossed 2.73 10 Thick 4.20 10 Thin 8.50 10 a.Complete the ANOVA summary table. b.Is Fobt significant at = .05; at = .01? c.Perform post hoc comparisons if necessary. d.What conclusions can be drawn from the F-ratio and the post hoc comparisons? e.What is the effect size, and what does this mean? f.Graph the means. #14. A researcher has been hired by a pizzeria to determine which type of crust customers prefer. The restaurant offers three types of crust: hand-tossed, thick, and thin. Following are the mean number of 1-inch pieces of pizza eaten for each condition from 10 subjects who had the opportunity to eat as many pieces with each type of crust as they desired. The ANOVA summary table also follows. Source df SS MS Subject 2.75 Between 180.05 Error 21.65 Total 204.45 Crust Type Mean n Handtossed 2.73 10 Thick 4.20 10 Thin 8.50 10 a.Complete the ANOVA summary table. b.Is Fobt significant at = .05; at = .01? c.Perform post hoc comparisons if necessary. d.What conclusions can be drawn from the F-ratio and the post hoc comparisons? e.What is the effect size, and what does this mean? f.Graph the means