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QUESTION 2 A study measured brain activity in the hippocampus while 24 participants studied a list of words

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QUESTION 2 A study measured brain activity in the hippocampus while 24 participants studied a list of words. Afterwards. each participant was asked to recall as many of the words as they could. For each participant. the researchers conducting the study calculated the difference in hippocampus activity for words remembered minus activity for words forgotten. Across participants, the mean difference was 4.52 and the standard deviation of differences was 17.6. The researchers use the T distribution to test the null hypothesis that the mean difference in the population equals zero. What is the T score? : QUESTION 3 Which of the following statements are true regarding R2, the proportion of variance explained? Select all that apply. a. For a categorical explanatory variable. R2 is the sum of squares between—groups divided by the total sum of squares. b. D If an explanatory variable is totally unrelated to a response variable. then the R2 will be —1_ D '3' If the Pearson correlation coefficient between an explanatory and response variable is 40.3, then the explanatory variable does not explain any variance in the response variable. Dd ' If R2 is high__ it must be the case that the explanatory variable causes differences in the response variable. D '9- If two explanatory variables are similar, they will probably explain a similar proportion of variance in a response variable.