A. ElITNl) 
135 
Type IV. area, for the cubic which bounds Type IV. asymptotes to the vertical line 
/Sj = 32, and the biquadratic asymptotes to the vertical line /3i = 50 as shown on 
the diagram. 
Of course much of Diagram B extends beyond the values of /Sj and /Sj that 
we are familiar with in actual frequency distributions. For practical purposes 
Diagram A drawn to a much larger scale suffices, and guides the statistician to 
the appropriate type and to the probable errors. Nevertheless Diagram B will 
indicate many points of much theoretical interest, and serves to show where 
failure in curve fitting is likely to arise. 
