$2\mathrm{.}8$ Fair Value Measurements. The text discusses inputs managers might use to determine fair values of assets and liabilities and identifies different classifications of assets identified in SFAS No$.157.$ Suppose a major university endowment has investments in a wide array of assets, including $($a$)$ common stocks; $($b$)$ bonds; $($c$)$ real estate; $($d$)$ timber investments, which receive cash flows from sales of timber; $($e$)$ private equity funds; and $($f$)$ illiquid asset$-$backed securities$.$ Consider how the portfolio manager would estimate the fair values of each of those classes of assets, and characterize the inputs you identify as Level $1,$ Level $2,$ or Level $3.$