Question 1011985: Can someone please help?
Suppose IQ scores were obtained from randomly selected twins. For 20 such pairs of people, the linear correlation coefficient is 0.793 and the equation of the regression line is ModifyingAbove y with caret equals 24.46 plus 0.75 xy=24.46+0.75x, where x represents the IQ score of the twin born first twin born first. Also, the 20 x values have a mean of 106.43 and the 20 y values have a mean of 103.9. What is the best predicted IQ of the twin born second twin born second, given that the twin born first twin born first has an IQ of 106? Use a significance level of 0.05.
The best predicted IQ of the twin born second twin born second is ___?
(Round to two decimal places as needed.)
Answer by MathTherapy(10555) (Show Source):
You can put this solution on YOUR website! Can someone please help?
Suppose IQ scores were obtained from randomly selected twins. For 20 such pairs of people, the linear correlation coefficient is 0.793 and the equation of the regression line is ModifyingAbove y with caret equals 24.46 plus 0.75 xy=24.46+0.75x, where x represents the IQ score of the twin born first twin born first. Also, the 20 x values have a mean of 106.43 and the 20 y values have a mean of 103.9. What is the best predicted IQ of the twin born second twin born second, given that the twin born first twin born first has an IQ of 106? Use a significance level of 0.05.
The best predicted IQ of the twin born second twin born second is ___?
(Round to two decimal places as needed.)
I'll get you started on this.
1) Calculate the critical t-value (groups consist of < 30 members)
2) If the absolute value of the linear correlation coefficient (r) is > the critical t-value, a LINEAR CORRELATION EXISTS between
the 2 groups (younger and older twins) of IQs. Thus, the regression equation: ŷ, or can be used to predict
the IQ of the younger twins (twins born second), by substituting the x-value 106 into the equation.
3) However, if the absolute value of the linear correlation coefficient (r) is ≤ the critical t-value, a LINEAR CORRELATION DOES NOT
exist between the 2 groups (younger and older twins) of IQs. Thus, the best predictor of y-hat or the younger twins' IQ is y:
the mean of the group: twin born second, or the younger twins (103.9)
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