520 ILLINOIS STATE ACADEMY OF SCIENCE 



By a study of the last two charts it is easy to deter- 

 mine whether a student whose I. Q. placed him in quin- 

 tile 1, was also placed in quintile 1 by his Algelira 

 grade. If so, there is a total correlation between his 

 I. Q. and his Algebra grade. If by his I. Q. he is in 

 quintile 2 but by his English grade he is in quintile 3, 

 there is a variation of one quintile. It is readily ob- 

 served, therefore, that there may be a total correlation, 

 or a variation of one, two, three, or even four quintiles. 



Checking through the two charts the following corre- 

 lations and variations are discovered, — 



Fall Term, Section One 



ALGEBRA 



1. Ten students had a total correlation of quintiles 

 in their I. Q.'s and Algebra grades. 



2. Fourteen students had a A^ariation of but one 

 quintile in their I. Q.'s and Algebra grades. 



3. One student had a variation of three quintiles in 

 his I. Q. and Algebra grade. 



