me spekt em want yu tu find a formula for a kerv thru em points . . . then dy/dx=slope . . . points dont quite make a strate line, but maebee em let yu . . . draw a strate line approx tu the points . . . if so, figger our y=mx+b..... first point=(0,0), so b=0 shood werk . . . last point=(1.5,755) . . . slope=deltay/deltax=755/1.5=503.33333333333333333... slope also =dy/dx then EVALUATE it at x=0.75...plug in 0.75 intu equashun