Volume $=\frac{1}{3}h(r_1^2+r_1{r}_2+r_2^2)$

$3$

From the data recorded by the LA DWP$,$ Mono Lake stood at $6,406\mathrm{.}9$ ft in June $1954,$ and it had

fallen to $6,391\mathrm{.}2ft$ by June $1964.$ Surface area of the lake in June $1954$ was $89\mathrm{.}4mi2$; surface area of

the lake in June $1964$ was $77\mathrm{.}0mi2.$

Assuming the lake is about circular, determine the respective radii of the lake in $1954$ and $1964$

in $m.$

Calculate the change in storage $($volume lost$)$ of Mono Lake over the $10-$year period from June

$1954$ to June $1964.$

Calculate the annual change in storage over this period $($m$3/$yr$).$