QUESTION 1 1. It is possible to compute a correlation coefficient if we have 2. a pair of scores for one individual a set of scores for a group of individuals two sets of scores for the same group of individuals all of the above QUESTION 2 1. Which of the following explains why poor grades and poor attendance often go together? 2. poor grades might in part result in poor attendance poor attendance might result in poor grades a third factor may be responsible all of the above might be true QUESTION 3 1. Which value of r indicates the strongest degree of relationship? 2. -.79 -.91 .87 .62 QUESTION 4 1. Other things being equal, when the range of talent is reduced, r will 2. change in an unpredictable manner decrease remain the same increase QUESTION 5 1. In a scatter diagram, if the cluster of data points slopes from lower left to upper right, this indicates 2. a negative correlation a curvilinear relationship a positive correlation zero correlation QUESTION 6 1. The correlation between minutes of exercise per week and HDL (good cholesterol) is r = .45. Which of the following is a correct interpretation of the correlation? 2. A. As minutes of exercise per week increases, HDL levels decrease. B. As minutes of exercise per week increases, HDL levels increase. C. There is no relationship between exercise and HDL. D. Increased weekly exercise causes increased levels of HDL. QUESTION 7 1. A causal relationship between X and Y can be inferred 2. only for positive values of r any time r is other than zero only on grounds that go beyond the simple showing of a degree of relationship only for values of r that are near 1.00 QUESTION 8 1. Which value of r indicates the least amount of relationship? 2. .08 -.12 -.98 -.85 QUESTION 9 1. The correlation between reaction time and performance on a video game is r = -.35. Which interpretation of this correlation is correct? 2. A. There is no relationship between reaction time and video game performance. B. There is a positive relationship between reaction time and video game performance. C. Higher reaction times are associated with higher game performance. D. There is a negative relationship between reaction time and video game performance. QUESTION 10 1. The correlation coefficient is obtained between academic aptitude test score and academic achievement (1) among students in general, and (2) among honor students. Other things being equal, we expect 2. one to be negative, the other positive the second to be higher the two coefficients to be about the same the first to be higher QUESTION 11 1. In a given group, the correlation between height measured in feet and weight measured in pounds is +.68. Which of the following would alter the value of r? 2. height is expressed in centimeters weight is expressed in kilograms neither of the above changes will affect r both of the above changes will affect r QUESTION 12 1. The value of r is computed from raw scores. Which is likely to change the value of r? 2. each X score is multiplied by -1 each X score is converted to its corresponding percentile rank each X score is expressed as the number of incorrect answers rather than the number of correct answers all of the above are likely to change the value of r QUESTION 13 1. If r = -1.00 2. either the X scores or the Y scores must be negative X is of no use in predicting Y values of Y can be predicted from values of X without error the relationship becomes difficult to interpret QUESTION 14 1. If the standing in X is of no help in predicting standing in Y, then r is 2. -1.00 0 less than -1.00 indeterminate QUESTION 15 1. The standard error of estimate is a kind of 2. mean standard deviation variance median QUESTION 16 1. The least squares line of regression for predicting Y from X minimizes 2. Sy and Sx Sx Syx Sy QUESTION 17 1. Accuracy of prediction by the regression equation is enhanced by 2. (a) large samples (b) a linear relationship (c) both of the above (d) none of the above QUESTION 18 1. In predicting Y from X, the regression line is laid down so that the squared discrepancies between points and the line are minimized 2. (a) in the X dimension (b) in the Y dimension (c) in a direction perpendicular to the line (d) in all of the above dimensions QUESTION 19 1. The standard error of estimate measures variability of 2. predicted scores around the mean predicted scores around the regression line obtained scores around the regression line obtained scores around the mean QUESTION 20 1. Which value of r permits the greatest accuracy of prediction? 2. (d) -.81 (c) -.37 (b) +.27 (a) +.78 QUESTION 21 1. If a regression equation reads: Y' = .50X - 3, we know that 2. Y increases 1 unit for every 2 units of increase in X the correlation is negative Y increases 2 units for every 1 unit of increase in X Y(bar) is 3 units lower than X QUESTION 22 1. What information do we need to calculate r 2 ? 2. r and b r, mean of X, and mean of Y r and a and b r QUESTION 23 1. If a regression equation reads: Y' = 1.25X+23, we know that 2. A mistake has been made in calculating r. The correlation between x and y is positive. Nothing can be determined about the correlation between x and y. The correlation between x and y is negative. QUESTION 24 1. In one study, a correlation of -.49 is found between the number of hours of TV watched per week and high school GPA. According to this study ___________ of the GPA variance is associated with TV watching. 2. 24% 49% 70% 14% QUESTION 25 1. A large value of Syx/Sy may be expected when r is 2. -.75 +.25 -1.00 +.90 QUESTION 26 1. Fifty percent of Y variance is associated with variation in X when r is approximately 2. .7 .5 .25 .9 QUESTION 27 1. In a study concerned with the relationship between X and Y, it is found that 9% of the variance in Y is associated with X. This r XY must have been 2. .81 .30 .09 .08
Purchase answer to see full attachment