J
 
:5. This problem refers to the data on temperatures given in
the preceding problem. Consider the following two statements
(both of which are correct).

 

 A. The patients who have a temperature of 103 degrees upon
being admitted to the hospital have temperatures 2 full SD's
above the average admission temperature. Use of the regression
estimate shows that, 24 hours later, these patients have an
average temperature of 99.6 degrees. But the SD of all 400 of
the temperatures taken 24 hours after admission is 0.5, and 99
+ (2 x 0.5) = 100, so 99.6 degrees is less (by 0.4 degrees)
than 2 full SD's above the average of all 400 of the
temperatures taken 24 hours after admission. 
J 

 

 B.  The average of the 400 temperatures taken 24 hours after
admission to the hospital is 3 degrees lower than the average
of the 400 temperatures taken upon admission to the hospital. 
J 

Then    

 a.  Statements A and B are both explained by the regression
     effect.

 b.  Neither statement A nor statement B is explained by the 
         regression effect.

 c.  Statement A is explained by the regression effect, but  
         statement B is not.

 d.  Statement B is explained by the regression effect, but  
         statement A is not.