Question

Suppose IQ scores were obtained from randomly selected

twinstwins.

For

2020

such pairs of​ people, the linear correlation coefficient is

0.8670.867

and the equation of the regression line is

ModifyingAbove y with caret equals 5.44 plus 0.93 xy=5.44+0.93x​,

where x represents the IQ score of the

twin born secondtwin born second.

​Also, the

2020

x values have a mean of

96.2696.26

and the

2020

y values have a mean of

94.9594.95.

What is the best predicted IQ of the

twin born firsttwin born first​,

given that the

twin born secondtwin born second

has an IQ of

9494​?

Use a significance level of 0.05

Answer 1

Answer:

Given that,

Suppose IQ scores were obtained from randomly selected twins.

For 20 such pairs of​ people, the linear correlation coefficient is 0.867 and the equation of the regression line is Modifying Above y with caret equals 5.44 plus 0.93 x (y=5.44+0.93x​).

Where x represents the IQ score of the twin born the second.

​ Also, the 20 x values have a mean of 96.26 and the 20 y values have a mean of 94.95.

What is the best-predicted IQ of the twin born first:

Given that the twin born second has an IQ of 94.

Use a significance level of 0.05.

The regression line is,

y=5.44+0.93x​ ........(1)

When x=94,

From (1),

y=5.44+0.9 94

=5.44+​84.6

=90.04

Therefore, the best predicted IQ =90.04.