$5\mathrm{.}6$ Sample $4$ from the previous data set was flooded with crude oil, in several steps,

in order to displace the brine. The remaining water saturation and $V$ values

were measured at each of these displacement steps. Based on the measured data

given in the following and other data from problem $5\mathrm{.}5,$ calculate the true forma$-$

tion resistivity $R_t$ as a function of water saturation $S_w$ and subsequently deter$-$

mine the saturation exponent $n$ of the Archie's saturation equation.