Question

In an introductory stats course x = mid-term score and y = final-exam score. Both scores have a mean of 80 and a standard deviation of 10. The correlation between scores is 0.70. Find the regression equation. What would be the final-exam would be if one scored a 67 on the mid-term? Assume mid-term scores predict final-exam scores.

Answer 1

Let , X=mid-term score and Y=final score

Given : ,

Also ,

Now , the regression equation is ,

Where ,

'b' be the regression coefficient or slope and it is given by ,

And

'a' be the intercept of the regression equation and it is given by ,

Therefore , the regression equation is ,

For , x=67

Therefore ,

Therefore , the predicted final examination  score is 70.9