Using the table below, calculate the Standard Deviation of the portfolio:

Demand for Company Products	Probability of this Demand Occurring	Rate of Return if this demand Occurs (k)
Weak	0.10	-30%
Below average	0.25	-15%
Average	0.30	10%
Above Average	0.25	25%
Strong	0.10	45%

A firm purchases 150 acres of land for $195,000 and agrees to remit 17 equal annual end-of-year installments of $25,831.94 each. What is the true annual interest rate on this loan?