57. Examine the following graph. The vertical axis represents mean return and the horizontal axis represents standard deviation of return. Each of the five lines depicts all of the specific risk-return combinations that can be achieved by creating portfolios consisting of varying proportions of stocks X and Y, given a specific assumption as to the value of what factor? 1 2 3 4 5 58. As we increase the number of securities in a portfolio through either random or efficient diversification, total portfolio risk is expected to: 59. As we increase the number of securities in a portfolio through either random or efficient diversification, total market risk is expected to: 60. As we increase the number of securities in a portfolio through either random or efficient diversification, total unique risk is expected to: 61. As we increase the number of securities in a portfolio through either random or efficient diversification, average unique risk is expected to: 62. Under what circumstance is it possible for a pricing model to indicate that a stock is overpriced when, in fact, the stock is correctly priced