xxxviii Tables for Statisticians and Biometriciaus [XVIII — XX 



regard to the spacings of the correlation curves, the value of the equiprobable 

 correlation is under "0:3, say '027. In other words no significant association can be 

 asserted. 



In the case of O ov = 1941 we are thrown back on the original formulae*. In 

 the first place we must find P for the given value of ^ 2 , i.e. - 7080 (see p. xxxv). 

 But for w'= 4 from formula (xxix), 



= 2 (-200,0578 + -280,0088 x "84142} 

 = -871,3256. 

 To obtain r we have to use the formula below, where O ov= "1941, and 



m— A ( • — 8), the /*„, fit, /i s being the normal moment functions of Table IX. 



W2irJ; 



e 



X 



P = 



■ -^5= [j Mo (V2«0 - & (V2//H-)} - lj ^ (V2m) - to (^2mr)j 



- sss- !/ " c (V ^" } " ^ (V2Vir)1 + m& !ms (V2 ~' 7t) ~ * ( vi ™ r >5j 



(xxxii). 



Substituting the values of n a,. = -1941 and V2wt = 4-852,107, we have for 



r =03, P= -90550, 

 r = -04, P= -86501. 

 Whence for P = -87133, we have r = -038. 



We now turn to the three cases which fall inside Table XX. 



(2) Eye-colour, Father and Son. 



log x 2 = 2-1249 „<7, = -0514, 



r = 0-5 log x" - 2-0942 

 n0 -, = 0o ^ = o f) j^ ^ = 2 2748 



r-06 log x 2 = 2-1239 

 ^,-•06 5=0 . 7 i og%2= 2-2935. 



Linear differences will suffice 



„<r, = -05 r = 0-5 +.^[1] = 0-517, 



o£r) . = . OG r = 0-G+;^[-l] = 0G01. 



Hence O o- r = -0514 gives 



r = -517 + ^x-084 



= •517 + -012 = -529. 



* Drapers' Company Research Memoirs. Biometrie Series VII. "A Novel Method," etc.: see 

 pp. 12, 13. 



