Problem $14-21$ Optimal Cash Return Point $($LG$14-8)$

HotFoot Shoes would like to maintain its cash account at a minimum level of $$27,000,$ but expects the standard deviation in net daily cash flows to be $$4,200,$ the effective annual rate on marketable securities to be $6\mathrm{.}7$ percent per year, and the trading cost per sale or purchase of marketable securities to be $$220$ per transaction.

What will be its optimal cash return point? $($Use $365$ days a year. Do not round intermediate calculations. Round your answer to $2$ decimal places.$)$