Veggie Burgers, Inc., would like to maintain their cash account at a minimum level of $245,000, but

Question:

Veggie Burgers, Inc., would like to maintain their cash account at a minimum level of $245,000, but expect the standard deviation in net daily cash flows to be $12,000, the effective annual rate on marketable securities to be 3.7 percent per year, and the trading cost per sale or purchase of marketable securities to be $27.50 per transaction. What will be their optimal upper cash limit?