Below, molecular weight data for a polytetrafluoroethylene material are tabulated.

Compute

$($a$)$ the weight$-$average molecular weight,

$($b$)$ the degree of polymerization

$($c$)\%$ of crystallization

Consider a unit cell volume of $5\mathrm{.}39{10}^{-22}c\frac{m^{-3}}{?}$ unit cell, ${}_s=2\mathrm{.}2\frac{g}{c}{m}^3,{}_a=2\mathrm{.}0\frac{g}{c}{m}^3,$ number of repeating units in a

unit cell is $7\mathrm{.}5$