The standard deviation of molecular weight M, for a polymer sample based on the number distribution is defined as [ x (M, - M,)2 An alternative definitions is a standard deviation based on the weight distribution Ow [ WI(M, - MW)2 (a) In class, we derived a relationship between the standard deviation and the dispersity M,/M,, starting with the first equation above. Start with the second equation and use similar arguments for the definition of Ow to show that Ow /Mw*= M2/M, - 1. (b) Based on your derivation result in part (a) and the relationship between the dispersity and o, show that M, 2 MW 2 Mm