Section $3.$B of this chapter describes a fishing$-$boat game played in a small coastal town. When the best$-$response rules for the two boats have been derived, rationalizability can be used to justify the Nash equilibrium in the game. In the description in the text, we take the process of narrowing down strategies that can never be best responses through three rounds. By the third round, we know that R the number of barrels of fish brought home by boat $1)$ must be at least $9,$ and that S $($the number of barrels of fish brought home by boat $2)$ must be at least $4\mathrm{.}5.$ The iterative elimination process in that round restricted R to the range between $9$ and $12\mathrm{.}75$ while restricting S to the range between $4\mathrm{.}5$ and $7\mathrm{.}5.$ Take this process of narrowing through one additional $($fourth$)$ round and show the reduced ranges of R and S that are obtained at the end of that round