Age, hours studied, and prediction: In How
It Works 15.2, we calculated the correlation coefficient...

Question

Age, hours studied, and prediction: In How
It Works 15.2, we calculated the correlation coefficient between students’ age
and number of hours they study per week. The correlation between these two variables
is 0.49.

1. Elif’s z score for age is −0.82.
What would we predict for the z score for the number of hours she studies per
week? 

2. John’s z score for age is 1.2. What
would we predict for the z score for the number of hours he studies per week? 

3. Eugene’s z score for age is 0. What
would we predict for the z score for the number of hours he studies per week? 

4. For part (c), explain why the concept of
regression to the mean is not relevant (and why you didn’t really need the
formula).

Rajeswari · Accepted Answer

108895 Assignment
Age, hours studied, and prediction: In How It Works 15.2, we calculated the correlation coefficient between students’ age and number of hours they study per week. 
The correlation between these two variables is 0.49.
Solution:
We have to recollect the fact that the correlation coefficient, r, is the slope of the regression line when both X and Y are expressed as Z scores.
In other words, r is the average of cross products of Z_x and Z_y
i.e.

Age, hours studied, and prediction: In How It Works 15.2, we calculated the correlation coefficient between students’ age and number of hours they study per week. The correlation between these two...

Solution

Answer To This Question Is Available To Download

Related Questions & Answers

Submit New Assignment