The portfolio is considered to be less risky if its volatility is low. The higher standard deviation the more risky is the project. For Duke Energy and Microsoft the investment portfolio required is risk free investment. To calculate the risk free rate we calculate using the formula;
Var Rp = x1 2Var R1 + x2 2Var R2 +2 x1 x2 Corr (R1, R2) SD1 SD2
Var Rp = 0.14 + 0.44 + 2 (1) * (-1) * 6% * 24%
Solving for this we get the risk free investment at 4%.
As the amount $3,900 is already debited and at the year end, the remaining amount of office will be posted to the account of the office supplies expense against the office supplies account.
Working Note:
Amount = Debited amount of office supplies - Offices supplies on hand
