liv 



Tables for Statifiticians and Biometriciana [XXX 



Hence r, h being known, Fis a tabled iutegral for each value of Y. Accordingly 



by aid of Table II we know e " -^ , and using a quadrature formula, djN can 



v27r 



be found for each value of li, k and r. 



Table XXX gives, for r = -80, -85, ^90, -95 and 1-00, and values of J, and /.■ 

 proceeding b}' •], the values of d/iV. For given values of h, k and djN, we can 

 then find r by interpolation from these tables. The process is for shorter than 

 that required by Table XXIX when we have to proceed to many terms. Un- 

 fortunately opportunity has not yet arisen for full)' completing similar tables 

 for r negative and over •80. 



Illustration. Determine the correlation in habits between Mother and Father 

 in Bradford. The data are 



Mother. 



ID 



Here {h + d)IN= -32017, {c + d)/N= -37441, and therefore h = -46722, k = -32020 

 from Table II. Also rf/A^= 476/1696 = -28066. 



Inspection of Table XXX shows that r will be likely to lie between -90 and '95. 



We extract from the Table for d/N: 





Habits Good 



Habits Bad 



Totals 



Habits Good 

 Habits Bad 



994 

 159 



07 

 476 



1061 

 635 



Totals 



11.^3 ' .-.13 



1696 



Hence : 



Thus : 





r=-90 



7j = ^4 



1 

 7i = -5 





r=^95 



7i=-4 



7i = -5 





■ 



/fc=-4 



•2943 



•2784 



•2728 

 •2602 



k=-4 



•3135 

 •2980 



•2898 

 •2787 















r=-90 



7.= -4 



7^=•5 





r= -95 



7i = ^4 



7i = -5 



/•= -32020 



■2911 



•2703 



k= -32020 



•3104 ' ^287 



6 

















r=-90 



7i= •46722 





1 

 r = -95 7( = •46722 







i-= -32020 



•2771 



/[■= -32020 -2951 



1 





