If cov(x,y)= 1260, ,and ,then the coefficient of determination is:
A)0.90
B)1.23
C)0.81
D)0.006

Question

If cov(x,y)= 1260,  ,and  ,then the coefficient of determination is:
A)0.90 
B)1.23 
C)0.81 
D)0.006

Quizplus · Accepted Answer

The coefficient of determination is the square of the correlation coefficient. Therefore, we need to first calculate the correlation coefficient as follows:

r = cov(x,y) / (std(x) * std(y))
r = 1260 / (√11ea78b9_2e3f_88ca_8379_9f0c17ffea44_TB4388_11 * √11ea78b9_2e3f_88cb_8379_19f14f6e153e_TB4388_11))
r ≈ 0.9

Therefore, the coefficient of determination is:

r^2 ≈ 0.81

Thus, the best choice is C with an explanation as stated above.

If Cov(x,y)= 1260, ,And ,Then the Coefficient of Determination