The Board of Directors at Reuel Enterprises, based in Zambia, has established a lower cash

control limit of US$$3,000.$ The daily interest rate on investments stands at $0\mathrm{.}03\%.$ The

company's standard deviation of daily cash is determined to be US$$400.$The switching cost per

transaction amounts to US$$22.$

Calculate the spread, the upper limit$,$ and the return point.