If the correlation between the IQs of identical twins is .86,then,in any group of identical twins,what percent of the variation in the "Y" twins' IQs is accounted for by knowing the IQs of their identical siblings (the "X's")?
A)22
B)43
C)74
D)86

Question

Quizplus · Accepted Answer

The correlation coefficient (r) measures the strength of the linear relationship between two variables. The coefficient of determination (r²) represents the percentage of the variation in one variable that is accounted for by the variation in the other variable. In this case, r² = 0.86² = 0.7396, which is approximately 74%. Therefore, knowing the IQs of their identical siblings can account for 74% of the variation in the Y twins' IQs.

If the Correlation Between the IQs of Identical Twins Is