218 Dr. L. Isserlis on the Variation of 



Here Q9999)* _ -9998 _ 



^~2000(-01)~ 20 " ' 



or f is about 5 times greater than R. 



On the other hand, although this is of less importance^ 

 the mean value will be very nearly equal to the true value,, 

 even in small samples, if the multiple correlation is very 

 high. 



Consider samples of ten drawn from a population for 

 which R = *9. 



Here fc ('19)* '0361 AA0A , 



or f is about 450 times smaller than R. 



(Hi.) We can now find 2e to ^ De same degree of 

 approximation (i. e. correct to 1/n). 

 Let us write 



So that 



v* + w- — 2uvw , . 



</> = X 2 = - - ^ =(j}(u, v, to) say 



(3-t-m")|^=2(i^-iw), 

 (l-tt*)M = 2(t;-tflu), 

 (1-^)1^=2^-^). 



(1^)1^=2, 



d« 2 



(l- 2 )^=2. 



OUQV 



( 1 - u 2 ) 2 ^^- = 4ww - 2v - 2u\ 



