Chapter 20, Problem 24P

As compared to the models from Probs. 20.22 and 20.23, a somewhat more sophisticated model that accounts for the effect of both temperature and chloride on dissolved oxygen saturation can be hypothesized as being of the form,

$o_s=a_0+f_3\left(T\right)+f_1\left(c\right)$

That is, a constant plus a third-order polynomial in temperature and a linear relationship in chloride are assumed to yield superior results. Use the general linear least-squares approach to fit this model to the data in Table P20.21. Use the resulting equation to estimate the dissolved oxygen concentration for a chloride concentration of 10 g/L at $T=20°\text{C}$.