THE STRAIGHT LINE LAW 



218. Example. The following values of x and y are supposed 

 to follow the law y = ax* + b Iog 10 <r. Test if this is so, and if so, 

 find the most probable values of the constants a and b. 



(a) Dividing throughout by x* the law becomes 



Hence, plotting -^ vertically and * horizontally will give a 



OC X 



straight line if the values follow the law. 



Fig. 146 shows the resulting straight line. 



2-0 



OOE 



003 006. 



FIG. 146. 



OG5 



ooe. 



Let A and B be two points taken on this straight line. 



2 F 



