$7.$ a$.$ U $=800$

H $=1200$

Estimated Annual Return $=$ $$8400$

b$.$ Constraints $1$ and $2.$ All funds available are being utilized and the maximum permissible risk is being incurred.

c$.$

Constraint Dual Values

Funds Avail. $0\mathrm{.}09$

Risk Max $1\mathrm{.}33$

U$.$S$.$ Oil Max $0$

d$.$ No$,$ the optimal solution does not call for investing the maximum amount in U$.$S$.$ Oil.