3 Suppose IQ scores were obtained from randomly selected twi

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Suppose IQ scores were obtained from randomly selected twins. For 20 such pairs of people, the linear correlation coefficient is 0.888 and the equation of the regression line is y=16.77+0.82x, where x represents the IQ score of the twin born first. Also, the 20 x values have a mean of 98.72 and the 20 y values have a mean of 97.5.

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.

(Hint: view the critical values of the Pearson correlation coefficient r)

The best predicted IQ of the twin born second is _______

(Round to two decimal places as needed.)

Solution

Answer:
y= 16.77 + .82x

x = 105 , so y = 16.77 + .82x*105 = 102.87 (Ans.)

The best predicted IQ of the twin born second is 102.87