A company purchased a piece of manufacturing equipment for an additional income. The expected income is $3,500 per semester. Its useful life is 9 years. Expenses are estimated to be $500 semiannually. If the purchase price is $34,000 and there is a salvage value of $4,500, what is the prospective rate of return(IRR) of this investmant? The MARR is 10% compounded semiannually.