$9\mathrm{.}1$ Using the rainfall and runoff data of a short duration, high intensity storm provided in Table $9\mathrm{.}18,$ create a unit hydrograph for the watershed and make an estimate of unit duration. The watershed drainage area is $169$ acres. The sum of the unit graph flow is $1022\mathrm{.}6$ cfs$.$

$9\mathrm{.}3$ For the unit hydrograph created in Problem $9\mathrm{.}1,$ mathematically show that the volume of runoff under the curve is equal to one inch.