Dataset: fertyld.dat Source: P.R. Johnson (1953). "Alternative Functions for Analyzing a Fertilizer-Yield Relationship", Journal of Farm Economics, Vol. 35, #4, pp 519-529. Description: Pounds of Nitrogen (lbs/acre) and yield (bushels) for n=7 plots. Models Fit (where X is in units of 20 lbs): Power Function: Y=a*(X**b) Polynomial: Y=a+(b*x)+(c*(X**2)) Mitscherlish Law: Spillman: Y=M-(a*(R**X)) Y=M*(1-(C*(e**(k*X)))) Variables/Columns Nitrogen/acre (lbs) 6-8 N/a in units of 20 16 Yield (bushels) 21-24