Stats answer all questions and answer the questions that say show your work on a separate paper. Answer all 27 questions and last time my assignment had 10 questions wrong
Microsoft Word - Psy 5 Exam 3.docx PSYCHOLOGY 5 MIDTERM EXAM #3 RAY GRIMM, Ph.D. Name: ________________________________________ Multiple Choice. Mark your answers on Midterm 3 in Quizzes in Canvas. When indicated, either show your work or attach (or hand copy) StatCrunch tables to this worksheet. If you do not show your work or attach the required tables, you will not receive credit for the problem even if you marked the answer correctly on Quiz – Midterm 3.. 1. A cognitive psychologist studied memory for manes after a group activity that lasted 20 minutes. Participants were not told that this was study of memory. After the group activity, participants were asked to name the other group members. The researcher randomly assigned 120 participants to one of three conditions: (1) group members introduce themselves once (one introduction only) (2) group members were introduced by the experimenter and by themselves (two introductions), and (3) group members were introduced by the experimenter and themselves and also wore name tags throughout the group activity (two introductions and name tags. What is the correct statistic for this study? A. z for a sample mean B. single sample t C. independent measures t D. repeated/related measures t E. independent measures ANOVA 2. Psychologist Anna Fisher and her colleagues conducted a study in which they researched whether kindergarten students learned better in decorated classrooms or undecorated classrooms, referred to as “sparse classrooms”. They wondered whether students would be less distracted and learn better without decorations such as posters, maps, and children’s artwork. The same group of children had science lessons in a classroom without decorations and in a classroom with decorations. The students took a test on the material after each condition. Each child received a percentage-correct score,, out of 100%, for each condition. Which is the correct statistic for their study? A. z for a sample mean B. single sample t C. independent measures t D. repeated/related measures t E. independent measures ANOVA 3. Speculating that early exposure to more number words might predispose children to like mathematics, researchers wondered if mothers used more, on average, number words with their preschool sons than with their preschool daughters. Each participating family included one mother and one child – either female or male. They recruited 60 families, 30 with a son and 30 with a daughter. They counted the how many number utterances the mother made toward her child. After conducting their research, which is the correct statistic they should use? A. z for a sample mean B. single sample t C. independent measures t D. repeated/related measures t E. one-way ANOVA Scenario 1 - Use for problems 4-8 A clinical psychologist wants to determine if anxiety scores are lower after 10 group therapy sessions than before the sessions. He has a group of 10 clients with anxiety take a standardized test that measures their anxiety before the 10 group sessions and then again after the 10 group sessions. The data are below. To get credit for the following problems, use StatCrunch and attach (or hand copy) the tables to the worksheet. Compute the D as Before– After. Use ? =. ??. Before Sessions After Sessions 15 10 13 12 12 12 9 8 15 14 11 10 14 13 10 9 9 9 11 11 4. Which of the following are correct regarding the null and research hypotheses? A. Ho: Group therapy sessions will reduce anxiety scores; H1: Group therapy will not reduce anxiety scores B. H0: Group therapy sessions will not change anxiety scores; H1: Group therapy will change anxiety scores C. H0: Group therapy sessions will not reduce anxiety scores; H1: Group therapy will reduce anxiety scores D. H0: Group therapy will not increase anxiety scores: H1: Group therapy will increase anxiety scores 5. What is the tobtained for this study? A. 1.84 B. 12.54 C. 2.40 D. .76 6. Compute the effect size. Show your work. A. .33 B. .58 C. .25 D. .76 7. The researcher in this study should A. Reject the null hypothesis B. Fail to reject the null hypothesis 8. Which of the following statements is the best summary of the results? A. Group therapy does not seem to lower anxiety scores. B. Group therapy does seem to lower anxiety scores. C. The difference between anxiety scores before and after the group therapy is probably created by sampling error. D. There was a significant difference between anxiety scores before and after group therapy sessions. 9. A teacher wants to estimate the amount of attitude change that would occur in a population of high school students if they watched a video on global warming. A higher score indicates a greater acceptance that human actions are at least partially responsible for long term raising temperatures. She measured the attitudes of 36 students, showed them the video and then measured their attitudes again. Use the data below to create a 95% confidence interval for the mean change in students’ attitudes. Show your work. Compute D as After - Before. Mean attitude before watching the video: Mbefore = 141; Mean attitude after watching the video: Mafter = 152; SD of mean attitude change (SDD) = 5.5 A. LB = 5.5, UB =16.5 B. LB = 9.45, UB = 12.55 C. LB = 10.08, UB = 11.92 D. LB = 9.14, UB = 12.86 10. A teacher wants to estimate the amount of attitude change that would occur in a population of high school students if they watched a video on global warming. A higher score indicates a greater acceptance that human actions are at least partially responsible for long term raising temperatures. She measured the attitudes of 36 students, showed them the video and then measured their attitudes again. Use the data below to create a 95% confidence interval for the mean change in students’ attitudes. Mean attitude before watching the video: Mbefore = 141; Mean attitude after watching the video: Mafter = 152; SD of mean attitude change (SDD) = 5.5 Which of the following is a correct interpretation of this confidence interval? A. The mean change in the population is likely to be between the upper and lower bounds. B. The mean change in the sample is likely to be between the upper and lower bounds. C. If the study were repeated 100 times, the mean change would be between the upper and lower bounds 95 times. D. The mean attitude after watching the video is likely to be lower than the lower bound and the mean attitude after watching the video is likely to be higher than the upper bound. 11. An appropriate example of a repeated measures design would be A. comparing individual attitudes about drinking before and after viewing a film on the topic. B. ascertaining the relationship between personality and achievement in school C. ascertaining whether a given sample is a good representative of a given population. D. comparing how men and women differ on memory tasks. Scenario 2 - Use for problems 12-18 A student completing a senior project decides to investigate stress levels among college students. Specifically, she wants to know if freshmen or seniors experience more stress. To assess stress levels she asks 12 freshmen and 12 seniors to complete a survey designed to measure stress levels. Scores on the stress survey are normally distributed and measured on an interval scale where higher numbers indicate greater levels of stress. The data are as follows: Freshmen: 20, 43, 56, 76, 45, 87, 12, 34, 65, 58, 42, 100 Seniors: 90, 30, 80, 60, 64, 37, 84, 27, 87, 54, 38, 92 To get credit for the following problems, use StatCrunch and attach (or hand copy) the tables to the worksheet. 12. Respectively, what are your Independent Variable (IV), Conditions (C) and Dependent Variable (DV)? A. IV – Freshman, C – Seniors, DV- Stress score. B. IV – Stress score, C – Freshman & Seniors, DV – Class Grade C. IV – Senors, C – Freshman, DV – Stress score D. IV – Class Grade, C – Freshman & Seniors, DV – Stress score 13. Select the appropriate research hypothesis for this statistical analysis. A. µ1≠ µ2 B. µ1 = µ2 C. µ1 ≤ µ2 D. µ1 ≥ µ2 E. µ1 < µ2="" 14.="" if="" the="" researcher="" had="" computed="" the="" statistical="" analysis="" by="" hand,="" what="" would="" be="" the="" correct="" critical="" region="" (?=".05)" a.="" reject="" h0="" if="" t=""> 2.0739 B. reject H0 if t < −1.7171="" c.="" reject="" h0="" if="" t=""> 2.0739 or t < −2.0739="" d.="" reject="" h0="" if="" t=""> 1.7171 or t < −1.7171 15. what is your tobtained? a. −0.85 b. 10.35 c. 7.53 d. 2.01 e. −0.35 16. which of the following is the best summary of the results? a. college seniors exhibited higher stress levels (m = 61.92, sd = 24.57) than did college freshman (m = 53.17, sd = 26.09), t(22) = .-.846, p =.204, d = .35. b. college freshman (m = 53.17, sd = 26.09), exhibit higher stress levels than college seniors (m = 61.92, sd = 24.57), t(22) = -.846, p =.204, d = .35. c. college seniors exhibited higher stress levels (m = 61.92, sd = 24.57) than did college freshman (m = 53.17, sd = 26.09), t(22) = .-.846, p =.407, d = .35. d. there were no significant differences −1.7171="" 15.="" what="" is="" your="" tobtained?="" a.="" −0.85="" b.="" 10.35="" c.="" 7.53="" d.="" 2.01="" e.="" −0.35="" 16.="" which="" of="" the="" following="" is="" the="" best="" summary="" of="" the="" results?="" a.="" college="" seniors="" exhibited="" higher="" stress="" levels="" (m="61.92," sd="24.57)" than="" did="" college="" freshman="" (m="53.17," sd="26.09)," t(22)=".-.846," p=".204," d=".35." b.="" college="" freshman="" (m="53.17," sd="26.09)," exhibit="" higher="" stress="" levels="" than="" college="" seniors="" (m="61.92," sd="24.57)," t(22)="-.846," p=".204," d=".35." c.="" college="" seniors="" exhibited="" higher="" stress="" levels="" (m="61.92," sd="24.57)" than="" did="" college="" freshman="" (m="53.17," sd="26.09)," t(22)=".-.846," p=".407," d=".35." d.="" there="" were="" no="" significant="">