Degree of polymerization (number-average vs weight-average)

What is the DPn and DPw if a sample consists of:
        50g of cellulose polymerized by 100 glucose molecules
        30g of cellulose polymerized by 200 glucose molecules
        20g of cellulose polymerized by 500 glucose molecules


Number-average degree of polymerization (DPn) - weighed by mole fraction (number of moles)
        MW of glucose = (c.a.) 180
        Number of moles should be 50 / (100*180) = 0.00277,  0.000833,  0.000222, respectively.
        DPn = (0.00277*100 + 0.000833*200 + 0.000222*500) / (0.00277+0.000833+0.000222) = 145
        Experimentally, it is determined by measuring the osmotic pressure of polymer.


Weight-average degree of polymerization (DPw) - weighed by weight fraction
        DPw = (50*100 + 30*200 + 20*500) / (50+30+20) = 210
        Experimentally, it is determined using Rayleigh light scattering.