Question 36226
Let the interest rate be "x".
Start = 10,000
End of 1st year; 10,000(1+x)
End of 2nd year; 10,000(1+x)^2+3500(1+x)
EQUATION:
 10000(1+2x+x^2)+3500 + 3500x = 15,569.75
10,000x^2+23500x-2,069.75=0
*[invoke quadratic "x",10000,23500,-2069.75]
Interest rate is  8.5%
Cheers,
Stan H.