The ten columns of numbers on the far right of the figure and the twenty 

 rows of numbers on the bottom of the figure were set apart from the main part 

 of the figure, because of this tendency toward a vertical distortion, and divi- 

 ded into three groups with the rest of the data comprising a fourth group. 



The breakdown was as follows: 



The variances of the sub-areas were computed, and probability histo- 

 grams were drawn. The variances of areas B, C and D were all greater 

 than the variance of A, and since it was known that the total variance of Data. 

 Set 2 had about 400 degrees of freedom, these 400 degrees of freedom, were 

 apportioned in the ratio of the total number of points in each area. It was then 

 possible to apply the F test to the ratios of the variances. Table 11.2 shows the 



results which were obtained. 



174 



