$\text { Suppose that } R _ { 1 } = 6.81 + 0.86 t \text { and } R _ { 2 } = 6.81 + 0.35 t \text { model the revenue (in billions }$

$\text { Suppose that } R _ { 1 } = 6.81 + 0.86 t \text { and } R _ { 2 } = 6.81 + 0.35 t \text { model the revenue (in billions }$ of dollars) for a large corporation. The model $R _ { 1 }$ gives projected annual revenues from 2008 through 2015 , with $t = 8$ corresponding to 2008 , and $R _ { 2 }$ gives projected revenues if there is a decrease in the rate of growth of corporate sales over the period. Approximate the total reduction in revenue if corporate sales are actually closer to the model $R _ { 2 }$ . Round your answer to three decimal places.

A) $\$ 3.570$ billion
B) $\$ 24.990$ billion
C) $\$ 19.763$ billion
D) S29.645 billion
E) $\$ 12.495$ billion