ISWBl' = (Si, x )(tcril) + (X1_ X3) LOW Consider the research design described above. The results from the recylcing study are as follows: Treatment group mean: 6.30 Control group mean: 3.10 Sample size: 50 Standard error of the differences between the means: 0.80 Computer the lower bound of the confidence interval. (See the formula.) You may use this website to obtain the critical value for the t-test. Make sure to use .05 for the two-tailed probability and use the "twotailed T value" in your calculation. Or you can use a standard table of critical tvalues-Goog|e will find one. And make sure to use the treatment group mean as "Mean 1" in the formula. Your Answer: Answer I) View hint for Question 1 Question 2 (6 points) Consider your response to the previous question. Should you reject the null hypothesis? Why? A researcher thinks that listening to classical music reduces anxiety. She measures the anxiety of 10 persons then plays Mozart's "Eine Kleine Nachtmusik" (listen here if you want--you know the tune!) for them. Following that the researcher measures their anxiety again. (Note that anxiety is measured on a scale from 1 to 7, with higher numbers indicating increased anxiety.) Does the study support her hypothesis? Compute the upper bound of the confidence interval using the following data: mean of the difference scores (subtract pretest from posttest): -0.5 standard error of the difference scores: 0.5 The formula for the Cl upper bound is [standard error of the difference scores]*[t critical value]+[mean of the difference scores] Your Answer: Answer I) View hint for Question 3 Question 4 (6 points) Would you reject the null hypothesis given your response to the question above? Explain your decision. IUIIUWII lg qUUbLIUI l. A researcher is interested in examining whether type of meditation causes changes in people's level of happiness. She hypothesizes that: H1 : Zen meditation and Tantric meditation improve happiness over no meditation. She decides that she will need to measure everybody's happiness before they meditate to get a "baseline." And she randomly assigns people to condition (i.e., each participant has an equal likelihood of being in each condition) after she measures baseline happiness. 1. Using R (randomization to condition), X (administration of treatment), 0 (observation) notation, pick the experimental design that the researcher might use to investigate these hypotheses. (For more on R, X, 0 notation, see hereit will open in a new window.) 0 A) ROXO ROXO R0 0 Q B) OXRO OXRO 0 R0 0 C) ORXO ORXO OR o O D) RXO RXO XO Q E) XORO XORO ORO Question 6 (2 points) A researcher thinks that listening to classical music reduces anxiety. She measures the anxiety of 10 persons then plays Mozart's "Eine Kleine Nachtmusik" (listen here if you want--you know the tune!) for them. Following that the researcher measures their anxiety again. (Note that anxiety is measured on a scale from 1 to 7, with higher numbers indicating increased anxiety.) In this design, anxiety is the O A) criterion variable. 0 B) dependent variable. 0 C) independent variable. 0 D) outcome variable. Please read about the study on whether diet improves one's health. Click here --the page will open in a new window. Read both the "background" and "experimental design" sections. Please respond to this and the following question. Which of the following is the best description of the type of study? 0 A) A one-group pretest-posttest design 0 B) A nonequivalent control group design 0 C) A pretest-posttest control group design 0 D) A posttestonly control group design O E) Asurvey I) View hint for Question 7 Question 8 (2 points) A researcher hypothesizes that attitudes toward recycling can be improved by pro- recycling messages. She randomizes participants to either the treatment or control condition. The treatment group reads a short argument in favor of recycling then completes a questionnaire about attitudes toward recycling (on a scale of 1-7, with higher values indicating more positive attitudes). The the control group doesn't read anything but responds to the same questionnaire. In this design, the message about recycling is O A) the predictor variable. 0 B) the dependent variable. 0 C) the causal variable. 0 D) the independent variable. Question 9 (2 points) Which of the following designs should be evaluated with an independent samples t- test? C] A) Participants randomly assigned to either treatment or control groups. C] B) Participants measured on a pretest and a posttest, with an experimental manipulation between. D C) Evaluating gender differences in communication competence from bother- sister pairs. [3 D) All participants exposed to an experimental treatment and then measured on the dependent variable. [3 E) Gender differences in martial satisfaction from mixed-sex married couples. Question 10 (2 points) Imagine at some point during the diet study that researchers measured stress in both the experimental and control groups, with stress measured on a scale of 1-7 (higher numbers indicating higher stress). How would you interpret the following confidence interval? Upper bound: 1 Lower bound: .5 O A) Reject the null hypothesis: diet affects stress. 0 B) Fail to reject the null hypothesis: diet has no effect on stress. 0 C) Reject the null hypothesis: diet has no effect on stress. 0 D) Fail to reject the null hypothesis: diet affects stress. [> View hint for Question 2 Question 3 (8 points) A researcher thinks that listening to classical music reduces anxiety. She measures the anxiety of 10 persons then plays Mozart's "Eine Kleine Nachtmusik" (listen here if you want--you know the tune!) for them. Following that the researcher measures their anxiety again. (Note that anxiety is measured on a scale from 1 to 7, with higher numbers indicating increased anxiety.) Does the study support her hypothesis? Compute the upper bound of the confidence interval using the following data: mean of the difference scores (subtract pretest from posttest): 0.5 standard error of the difference scores: 0.5 The formula for the Cl upper bound is [standard error of the difference scores]*[t critical value]+[mean of the difference scores] Your Answer: Answer [> View hint for Question 3