Please help me with this one below is the problem and the answer that I got, but when I typed it in they system for my school says I am wrong.

Veggie Burgers, Inc., would like to maintain its cash account at a minimum level of $265,000 but expects the standard deviation in net daily cash flows to be $14,000, 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 $37.50 per transaction.

What will be its optimal cash return point?

=(((3*37.5*(14000)^2)/(4*3.7%))^(1/3))+265000

My answer 270301.2989

Please show what I am doing wrong.