years and 16. Suppose you observe the investment performance of 5,200 portfolio managers for 10 0 of the portfolio rank them by investment returns during each year. After 10 years, you find that 10 managers have investment returns that place them in the top half of the sample each and every year. Your friend suggests to you that such consistency in performance must mean that these portfolio managers are skilled and encourages you to invest your money with these portfolio managers. Explain (in a few sentences at most) whether your friend's assertion that the 10 portfolio managers must be skilled is justified and/or provide another plausible interpretation.