12 



BULLETIN 504, U. S. DEPARTMENT OF AGRICULTUEE. 



the coefficient is + .20. 

 r^,nr=+A8, and 



'^ptv.vfd^ + .42; 



'^pw.fcd^^ +.00; 



Similarly, r^^j = + .50, and 

 pw.c=+-48, and r'p^.cd= +-49; y'pw.j,/= +.39, and 

 •^pw.t^c^ +-43, and rp,„.rcd= + -46; rp^./c=+.85, and 

 ^pw.vfc= +-91, and rp^,vfcd= +-97. 



The remainder of the coefficients will not be taken up in detail, for 

 the same reasoning may be applied as has been used for those between 

 profit and weight. The notation is consistent throughout, and the 

 arrangement is such that any desired coefficient can be found. 



There does not seem to be any relation between cost at weaning 

 time and any of the other factors considered except profit, and since 

 ■cost at weaning time had more influence on profit than any of the 

 others, it might be of interest to know the relationship that would 

 have existed between profit and the other factors if the initial cost 

 had been constant. 



The coefficients are as follows : 



Tpw-C- 



T-pv-C- 



Tpf.c. 



Tpd.c. 



+.48 



+ .25 



-.38 



+ .16 



From these coefficients, it is evident that if the initial cost of all 

 the calves had been the same, the most important factor in deter- 

 mining the profit would have been the weight when marketed; the 

 other factors in the order of their importance being the total value of 

 feed consumed, the price per pound, and the date of sale. How- 

 ever, the correlation between profit and date of sale is still too small 

 to be important. 



The statement has already been made that the apparent correla- 

 tion between weight and value per hundredweight {r=-\-.6&) is due 

 to the effect of other factors. A study of the coefficients obtained 

 when these other factors are taken into consideration shows that 

 when the influence of date of sale is eliminated, the coefficient is re- 

 duced to +.31 ; when the influence of the value of feed consumed is 

 eliminated, the coefficient becomes -|--^S? ^^^ when the two factors 

 are taken into account simultaneously, the coefficient is -\-.14:. This 

 shows that the quantity of feed consumed per head was responsible 

 for nearly as much of this correlation as was the date of sale, and 

 that the two together account for practically the whole of it. In 

 other words, the value of feed consumed and the date of sale need 

 to be considered simultaneously here, because the later the date of 

 sale, the longer is the feeding period, and consequently the greater 

 the quantity and value of feed consumed. 



The gross correlation between date of sale and value per pound is 

 shown by the coefficient +.61, and that between total value of feed 

 consumed per head and value per pound, by the coefficient +.65. 



