Two models, $R_1$ and $R_2,$ are given for revenue $(in$ billions $of$ dollars per year$)$ for a large

corporation. Both models are estimates $of$ revenues for $2007$ through $2011,$ with $t=7$

corresponding $to2007.$

$R_1=7\mathrm{.}28+0\mathrm{.}21t+0\mathrm{.}028t^2$

$R_2=7\mathrm{.}28+0\mathrm{.}1t+0\mathrm{.}014t^2$

Which model $is$ projecting the greater revenue?

The model $R_1$ projects greater revenue than $R_2.$

The model $R_2$ projects greater revenue than $R_1.$

The model $R_1$ projects the same revenue $as{R}_2.$

How much more total revenue does that model project over the five$-$year period? $(Round$ your

answer $to$ two decimal places.$)$

$

billion