Consider the sample regression equation = 100 + 10x, with an R² value of 0.81. Which of the following is the value of the sample correlation between y and ? A) −0.90 B) −0.81 C) 0.81 D) 0.90

Question

Quizplus · Accepted Answer

The sample correlation (r) is the square root of the coefficient of determination (R²), which is 0.81. Taking the square root of 0.81 gives us 0.9, so the value of r is 0.9. Since the slope of the regression line is positive (10), the correlation must also be positive. Therefore, the only answer choice that is both positive and closest to 0.9 is D) 0.90.

Consider the Sample Regression Equation = 100 + 10x