单选题 Robert Lamy is an equity advisor. One day he gathered information about three microeconomic variables X, Y, Z. He noticed that whenever variable X increased by one unit, variable Y decreased by 0.3 units but variable C increase by 0.3 units. The correlation between variables X and Y and the correlation between variables X and Z, respectively, are closest to: Correlation between Correlation between Variables X and Y Variables X and Z ①A. -0.3 1.0 ②B. -0.3 0.3 ③C. -1.0 1.0 A．① B．② C．③

【正确答案】 C

【答案解析】The estimated slope coefficient is interpreted as the change in the dependent variable for a one-unit change in the independent variable. The correlation coefficient, r, is a measure of the strength of the relationship between two variables. Correlation is a unitless measure of the tendency of two variables to move together. The correlation coefficient is bounded by+1(the variables move together perfectly) and -1 (the variables move exactly opposite of each other).