Karl Pearson 
09 
I find the following results : 
Mean age : all Boys : Sirdar Road, 10'6456 
Laxon Street, 10-3092 
Anaemic Boys : Sirdar Road, 10'5444 
Laxon Street, 10-0430 
Standard Deviation for ages : all Boys : Sirdar Road, 2-019 
Laxon Street, 1-904 
For the girls we have : 
Mean age : all Girls : Sirdar Road, 10-6667 
Laxon Street, 10-3392 
Anaemic Girls : Sirdar Road, 10-8000 
Normal Girls*: Laxon Street, 10-2634 
Standard Deviation for ages: all Girls : Sirdar Road, 1-852 
Laxon Sreet, 1-951 
I will illustrate the general process on the Sirdar Road boys : 
pja, = (10-5444 - 10-6456)/2 019 
= --1012/2019 = --0512. 
Again ^1 - a) = 135/364 = -3709, thus i (1 + a) = -6291. In Sheppard's Tables 
this corresponds to a;/o- = -33 and gives for the corresponding ordinate z the value 
•3778. 
Hence q/a, = z/^(l - a) = -Sl78/-S109 
= 1^0186. 
Accordingly r = (p/a,)/(q/ a.;) = --0ol2/l-0186 
= - •0503. 
The negative sign indicates that anaemia in boys decreases with age, i.e. the 
age of the anaemic boys is less than that of all boys. The girls at Sirdar Road 
give a plus correlation = + -0627. Treated in the same manner the Laxon Street 
boys give — -1632. In the case of the girls at the latter school the correlation is 
+ -0373, the normal girls having a lower age than all girls. Thus we find : 
Correlation of Age and Anaemia. 
Boys 
Girls 
Sirdar Road 
Laxon Street ... 
- -0503 
- -1632 
+ •0627 
+ ^0373 
* It is necessary to take the normal and not the anaemic girls as the former are in this school in the 
minority. 
13—2 
