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9. Which of the following a) Effect size c) Alpha level 10. When it comes to power, what one factor does the researcher have the most control over to increase porver? A) Effect size b) Sample variability c) Sample size d) Alpha 11. To examine the effects of physical exercise on academic performance twenty students were randomly assigned to one of two conditions. The control condition was kept as sedentary as possible. They were asked to sit as much as possible and walk slowly if they had to go somewhere. The exercise group was asked to minimize sitting and stand as much as possible, run when they had to go somewhere, and overall try to be as active as possible. After two weeks they were all given the same exam in a nuclear physics class. The scores obtained from the students are shown below. Sedentary Group 70 28FF2P2R2 80 77 77 79 73 76 has no impact on power? b) Standard Error of the mean d) If you use a one or two tailed significance test 79 74 81 Active Group 89 86 88 89 85 94 91 90 95 96 a) Calculate descriptive statistics (mean, standard deviation) for each group and create a table.(1 pts) b) Create a bar graph showing the mean and standard deviation for each group. (1 pts) c) Calculate the standard deviation of the combined sample (equation pg. 213)(2) d) Calculate the effect size. (formula pg 213) (2 pts) e) Calculate a confidence interval for the difference between the means (equations pg. 213)(2 pts) (use the N₁-N₂ formula for the standard error of the difference) (2 pts) f) Conduct a t-test to see if there is a significant difference between the means (formula pg. 220)(2 pts) g) Write a brief sentence explaining the results of this study. Did being active have any impact on their exam scores? (2 pts)

1. In an experiment the group that receives no treatment and is used as the basis for comparison is referred to as what? a) Experimental Group c) Random Group 2. When comparing two groups, what is the first step in the analysis of the data? b) Calculate the effect size d) Do a Null Hypothesis Significance Test 3. In a paired-sample design, what kind of design is being used if the scores occur naturally, like a person's weight and height? a) Repeated measures b) Matched pairs a) Calculate means for each group c) Calculate confidence intervals Name Dawn 4. What is the most common formula for degrees of freedom? a) N+1 c) N-2 d) N-3 b) N-1 5. A biology instructor had a class on snakes and their habitats. One the first day of class students were asked to rate their fear of snakes on the 30 point fear of snake scale (The higher the score, the greater their fear of snakes). At the end of the semester each student again rated their fear of snakes on the same 30 point scale. The following data was collected. Lindsay Natalie Carolyn Troy Kay Russ Larry Mary Loretta 1" day 26 -223922888 25 b) Control Group 15 18 13 14 26 Last day 16 14 22 12 c) Natural pairs 15 11 13 17 19 19 26 Because the scores in each pair are linked together (a pretest score and a posttest score) this will be a paired sample analysis. (show all your work on scratch paper) a) Calculate the descriptive statistics (mean and standard deviation) for each group and create a table.(1 pts) b) Create a bar graph showing the mean and standard deviation for each group. (1 pts) c) Calculate the standard deviation of the difference scores (formula page 209) (2 pts) d) Calculate the effect size for this paired sample design, (formula pg 209) (2 pts) e) Calculate a confidence interval for the difference between the means (formula pg. 210) (2) f) Conduct a t-test to see if there is a significant difference between the means (formula pe 219) (2 pts) 6. A researcher was interested in how the time of a class impacts a student's performance on a 90 minute endurance exam. Sixteen students were randomly divided into two group, eight in the 8:00 class and eight in the 1:00 pm class. The following scores were obtained on the 90 minute exam. 8:00 group PISIERER 79 84 82 74 77 70 74 78 1:00 pm group 84 87 79 85 84 88 76 89 With this data do the following. Because each person is only in one group these are independent samples and will use different equations that the previous question. (show your work) a) Calculate descriptive statistics (mean, standard deviation) for each group and create a table.(1 pts) b) Create a bar graph showing the mean and standard deviation for each group. (1 pts) c) Calculate the standard deviation of the combined sample (equation pg 213)(2) d) Calculate the effect size. (formula pg 213) (2 pts) e) Calculate a confidence interval for the difference between the means ((equations pa 213)(2 pts) (use the N₁-N₂ formula for the standard error of the difference)(2 pts) f) Conduct a t-test to see if there is a significant difference between the means (formula pg. 220)(2 pts) g) Write a brief sentence explaining the results of this study. Did the time the test was taken have a significant effect on the final scores? (2 pts) 7. A good conclusion should include what four pieces of data? (4 pts) 8. List the four common complaints that are made against the use of Null Hypothesis Significance testing (4 pts)