So assuming simplet interest
find the change to find the interest
change=186000-129000=57000
simple interest=time times rate times principal
time is in years (8)
rate is in decimal
principal is amount invested (129000)
so
interest is 57000
57000=(8)(r)(129000)
57000=1032000r
divide both sides by 1032000
0.05523255813953488372093023255814=r
or
5.523255813953488372093023255814%
rounded
5.5%
Step-by-step explanation:

Answer:
1/19
Step-by-step explanation: