$24\mathrm{.}1.$ Suppose there is a representative market maker with constant absolute risk aversion a$,$ and competition forces the bid and ask to the prices that make the market maker indifferent about trade. Suppose there is no information in market orders, which are of a unit size. Assume that the future value of a unit of the asset is normally distributed with mean u and variance $\backslash$sigma $^2.($a$)$ Leto denote the number of shares owned by the market maker before trade. Compute the ask and bid prices. Show that, even though the bid and ask depend on $0,$ the bid$-$ask spread does not.