Suppose IQ scores were obtained from randomly selected twins

Suppose IQ scores were obtained from randomly selected twins. For 20 such pairs of people, the linear correlation coefficient is 0.871 and the equation of the regression line is ModifyingAbove y with caret equals 4.84 plus 0.96 x , where x represents the IQ score of the twin born first. Also, the 20 x values have a mean of 98.71 and the 20 y values have a mean of 99.6. What is the best predicted IQ of the twin born second, given that the twin born first has an IQ of 105? Use a significance level of 0.05.

The best predicted IQ of the twin born second is ________?

Solution

To get the best predicted IQ, we simply plug in the value of x to the regression equation.

Here,

y^ = 4.84 + 0.96x

Thus, if x = 105,

y^ = 4.84 + 0.96*105 = 105.64 [ANSWER]