Variables X and Y are perfectly negatively correlated. Given only this information, if you run a regression of Y against X, which of the following is/are true?
I. The intercept term is zero.
II. The slope equals 1.
III. R-square equals 1.
IV. The percentage of unexplained variance equals 100%.
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A. B. C. D. E. F. G.E
If Y = aX + b, then X and Y are perfectly negatively correlated for any value of b and any negative value of a. Hence, given the information in the question, the slope must be negative but not necessarily equal to 1 and the intercept term cannot be determined. Since the correlation coefficient is 1, R-square is also 1, as expected, since all the variation in Y can be explained by variation in X. Note that the percentage of unexplained variance equals zero.