4. What is sunk cost? How should we take it into account when we are making financial decisions? 5. If our fixed costs total $500,000, our variable costs per unit are $40 and our sales price per unit is $90. How many units must we sell to achieve a target profit of $200,000? (hint: must first cover fixed costs then make additional profit to achieve target profit) 6. What is the expected return of a stock that has a beta of 1.4 if the risk free rate is 2% and the return of the market is 11%? 7. What is the beta of a portfolio that has the following investments? $50,000 in stock A with a beta of 1.2, $20,000 in stock B with a beta of 0.9, $100,000 in stock C with a beta of 1.6, and $30,000 in stock D with a beta of 0.6