5. Below, molecular weight data for a polytetrafluoroethylene material are tabulated. Compute (a) the number-average molecular weight, (b) the weight-average molecular weight, and (c) the degree of polymerization. Molecular Weight Range (g/mol) Xi Wi 10,000-20,000 0.03 0.01 20,000-30,000 0.09 0.04 30,000-40,000 0.15 0.11 40,000-50,000 0.25 0.23 50,000-60,000 0.22 0.24 60,000-70,000 0.14 0.18 70,000-80,000 0.08 0.12 80,000-90,000 0.04 0.07