10:12 < PSY230-M4-Assignment-SpringA202... Q2e. Calculate the mean from the sample of difference scores. Round the result to the hundredth (2nd place to the right of the decimal). [1 point: 0.5 if process is correct but answer is wrong] Q2f. Estimate the standard deviation of the population of difference scores. Round the result to the hundredth (2nd place to the right of the decimal). [1 point: 0.5 if process is correct but answer is wrong] Q2g. Calculate the standard error (standard deviation of the sampling distribution). Round the result to the hundredth (2nd place to the right of the decimal). [1 point: 0.5 if process is correct but answer is wrong] Q2h. Calculate the t statistic for the sample of difference scores. Round the result to the thousandth (3rd place to the right of the decimal). [1 point: 0.5 if process is correct but answer is wrong] Q2i. Figure out the degree of freedom, and then determine the critical & value(s) based on the type of test and the preset alpha level. [1 point total: 0.5 for df, 0.5 for critical t value] Q2j. Compare the t statistic with the critical t value. Is the calculated t statistic more extreme or less extreme than the critical value? Then make a decision about the hypothesis test, stating explicitly "reject" or "fail to reject" accordingly. [1 point total: 0.5 for each answer] Q2k. Interpret the result in 1 sentence to answer the research question (you may use the wording from the hypothesis or explain it in your own words) [0.5 point] Q21. Calculate the standardized effect size of this hypothesis test. Round the result to the hundredth (2nd place to the right of the decimal). [1 point: 0.5 if process is correct but answer is wrong] Q3. Paired-samples t test (8 points) In a cognitive psychology experiment, the researcher is interested in whether encoding condition has an effect on memory for a list of words. She recruits 12 subjects to participate in the experiment. Each subject comes to the lab twice to be tested in two different encoding conditions and their memory performance scores are listed below. The researcher would like to leave the hypothesis non- directional without predicting which encoding condition would lead to better memory, and she sets the significance level at = .05 for a 0= 3 Dashboard Calendar To Do Notifications Inbox 10:12 < PSY230-M4-Data-SpringA2023-1.xlsx Q1 Q2 Q3 Subject ID Encoding Encoding B 1 177 179 2 189 193 3 185 188 4 178 176 5 181 178 6 186 184 7 193 191 8 192 187 9 187 182 10 182 178 11 179 176 12 188 184 3 0= lopp 1000 Dashboard Calendar To Do Notifications Inbox 10:12 < PSY230-M4-Data-SpringA2023-1.xlsx Q1 Q2 Q3 Japanese Ca MPG 1 29 2 32 3 30 4 28 5 27 6 34 7 30 8 35 9 32 10 36 3 0= lopp 1000 Dashboard Calendar To Do Notifications Inbox < 10:12 PSY230-M4-Data-SpringA2023-1.xlsx Q1 Q2 Q3 Subject ID Age 70 1 74 Age 80 70 2 72 3 73 4 68 5 74 6 71 7 67 88 69 9 68 10 72 76783OSPER 71 69 65 70 70 3 lopp 0= 1000 Dashboard Calendar To Do Notifications Inbox 10:12 < PSY230-M4-Assignment-SpringA202... Q2) Paired-Samples & Test (11 points) A research project has been tracking the health and cognitive functions of the elderly population in Arizona. The table below shows the memory test scores from some elderly residents, tested first when they were 70 years old and again when they were 80 years old. The researcher wants to know if there is a significant decline in memory functions from age 70 to age 80 based on this sample. In other words, it is hypothesized that the memory score at age 80 is significantly lower than the memory score at age 70. So the null and alternative hypotheses should be directional. The alpha level was set at a = .05 for a one-tailed hypothesis test. Memory score Subject Age 70 Age 80 1 74 70 2 72 67 3 73 71 4 68 68 5 74 73 6 71 69 7 67 65 8 69 70 9 68 67 10 72 70 Q2a. Identify the dependent variable (this is the outcome measure) and the independent variable (this is what differentiates the two groups of data points being compared). [1 point total: 0.5 for DV, 0.5 for IV] Q2b. Explain why a paired-samples t test is appropriate for answering this research question. [0.5 point] Q2c. What would be the null and alternative hypotheses in both words and symbol notations? [1 point total: .5 for each hypothesis. Both the written form and the symbol notation need to be correct to get the 0.5 point for a hypothesis] Symbolic Written Symbol bank for copy & pasting: =3 m H: Null H: Alternative Q2d. Calculate the difference score by subtracting each Age 70" score from the associated "Age 80" score for each subject. Fill in the column in the table below for "difference score." [1 point total: deduct 0.5 for each error up to 1 point.] Hint: The difference score is calculated as (age 80 minus age 70), so a negative number indicates a decline in memory performance, which is the researcher's hypothesis. 3 lopp 0= Dashboard Calendar To Do Notifications Inbox