Simple interest formula = I = PRT where I = interest, P = principal, r = interest rate and t = time.
i = 806.20, p = 14,000 t = 250 days.
Change t to be fraction of a full year: t = 250/365
Now solve for r:
806.20 = 14000 x r x 250/365
Simplify :
806.20 = r x 9589.04
Divide both sides by 9589.04:
r = 806.20 / 9589.04
r = 0.08407
Multiply by 100 to get percent:
r = 8.41% (rounded to nearest hundredth)