The following data were measured for the viscosity of a $500 \mathrm{ppm}$ polyacrylamide solution in distilled water:

Shear Rate $\left(\mathbf{s}^{-1}\right)$	Viscosity $(\mathbf{c P})$	Shear Rate $\left(\mathbf{s}^{-1}\right)$	Viscosity $(\mathbf{c P})$
0.015	300	15	30
0.02	290	40	22
0.05	280	80	15
0.08	270	120	11
0.12	260	200	8
0.3	200	350	6
0.4	190	700	5
0.8	180	2,000	3.3
2	100	4,500	2.2
3.5	80	7,000	2.1
8	50	20,000	2

Find the model that best represents these data, and determine the values of the model parameters by fitting the model to the data. (This can be done most easily by trial and error, using a spreadsheet.)