If the standard deviations of X and Y are 15.5 and 10.8,respectively,and the covariance of X and Y is 128.8,then the coefficient of correlation r is approximately 0.77.

Question

Quizplus · Accepted Answer

The coefficient of correlation between X and Y can be calculated using the formula:

r = cov(X,Y) / (SD(X) * SD(Y))

Substituting the given values, we get:

r = 128.8 / (15.5 * 10.8) = 0.773

Since this value is close to 0.77, the statement "the coefficient of correlation r is approximately 0.77" is true. Therefore, the answer is A.

If the Standard Deviations of X and Y Are 15