Loan amount = $9,500

Monthly payments = $227.50
Time of loan contract = 5 years

True annual interest rate (to the nearest tenth) =

2 answers

9500 = 227.5( 1 - (1+r)^-60)/r
where r is the monthly rate
a very tough equation to solve ....

Wolfram says r = .01275 as the monthly rate

so annual rate compounded monthly = .153
or 15.3 %

equivalent annual rate:
1+i = 1.01275^12 = 1.164
or 16.4%
http://www.wolframalpha.com/input/?i=solve+9500+%3D+227.5%28+1+-+%281%2Bx%29%5E-60%29%2Fx

look at second line output, the negative rates are to be ignored.