19. Which of the following is not an aspect involved in computing the sum of products (SP) of deviations?

a. Dividing by the total number of participants

b. Adding the total X and Y scores across all participants

c. Subtracting the total sum of squares collapsed across all scores

d. Multiplying the X and Y scores together for each participant

20. Which of the following actions would have the effect of either changing the size or direction (sign) of a Pearson r value pertaining to a set of X and Y scores?

a. Dividing each X and Y score by a positive constant value

b. Multiplying each X and Y score by a negative constant value

c. Subtracting a constant value from each X and Y score

d. Adding a constant value to each X and Y score

21. For a two-tailed hypothesis test evaluating a Pearson correlation, what is stated by the null hypothesis?

a. There is a non-zero correlation for the general population.

b. The population correlation is zero.

c. There is a non-zero correlation for the sample.

d. The sample correlation is zero.

22. The Pearson correlation is calculated for a sample of n = 50 individuals. If a hypothesis test is used to determine whether the correlation is significant, which df value would be used for the t statistic?

a. df = 50

b. df = 49

c. df = 48

d. df = 25

23. In a test for significance of a Pearson correlation for a sample of n = 30 individuals, a researcher determines the critical value for the hypothesis test by using df = 29.

a. True

b. False

24. For a two-tailed hypothesis test evaluating the significance of a correlation, the null hypothesis states that the population correlation is zero.

a. True

b. False

25. As the sample size gets smaller, the size of the correlation needed for significance _____.

a. stays constant.

b. gets smaller.

c. gets larger.

d. This is impossible to determine based on the provided information.

26. The value obtained for the sum of products, SP, determines the sign (+/-) for the Pearson correlation value.

a. True

b. False

27. One or two extreme data points can have a dramatic effect on the value of a computed Pearson's r value for a correlation.

a. True

b. False

28. A set of X and Y scores has a Pearson correlation of r = 0.60. For these data, 60% of the variability in Y scores can be predicted from the relationship of the Y variable with the X variable.

a. True

b. False