d$.$ Construct a plausible graph that shows risk $($as

measured by portfolio standard deviation$)$ on the

$x-$axis and expected rate of return on the $y-$axis.

Now add an illustrative feasible $($or attainable$)$ set

of portfolios and show what portion of the feasible

set is efficient. What makes a particular portfolio

efficient? Don't worry about specific values when

constructing the graph$-$merely illustrate how

thinos look with "reasonable" data.