Suppose you borrow at the risk-free rate an amount equal to your initial wealth and invest in a portfolio with an expected return of 20 percent and a standard deviation of returns of 16 percent. The risk-free asset has an interest rate of 4 percent. Calculate the standard deviation of the resulting portfolio.

Which of the following statements is (are) true? i. free entry to a perfectly competitive industry results in the industry's firms earning zero economic profit in the long run, except for the most efficient producers, who may earn economic rent. ii. in a perfectly competitive market, long-run equilibrium is characterized by lmc < p < latc. iii. if a competitive industry is in long-run equilibrium, a decrease in demand causes firms to earn negative profit because the market price will fall below average total cost.