Question 5

To estimate the achievment score for a student with INTEL=30, just plug into the regression equation:

   ^
   Y = 24.9 + 1.26*30 = 62.7

i.e. we would guess an ACHSCOR of 62.7 for a student with INTEL=30. There is however quite a bit of uncertainty about this. This uncertainty comes from two sources: First, we have only guessed the line - we are not certain about the values 24.9 and 1.26. 2. And second, even if we knew the line exactly, we know that observations will not be exactly on the line but scattered around it.

 MTB > regress 'ACHSCOR' 1 'INTEL'

 The regression equation is
 ACHSCOR = 24.9 + 1.26 INTEL