124. Solving a chemistry problem

Using centrifugation under different conditions, two fractions of skimmed milk casein micelles were isolated, differing in sedimentation coefficients s and diffusion coefficients D. m2/s, the other has S2=8.00*10-11 s and D2=2.82*10-12 m2/s. The specific partial volume of both fractions is 0.700 cm3/g, the density of skimmed milk is 1.034 g/cm3. For both fractions, calculate the micelle molar masses and approximate aggregation numbers (number of casein molecules per micelle), assuming an average casein molar mass of 20 kg/mol.