The bar graph shows discretionary spending by full and part-time college students in some country from $140 , ,,,__.. .-, mg 0-2 2007 through 2013. The data in the graph can be @3120 modeled by the formula 0 = 1.2x2 +1.6(x +40), where D 4; represents discretionary spending among students, in $1 billions of dollars, x years after 2007. According to \"g $80 the formula, how much money did college students Discretionary Spending Among Students 3 $60 spend in 2011'? Does the model underestimate or g overestimate the amount of discretionary spending 'g $40 displayed by the bar graph? By how much? 5 $20 D 2007 2009 2011 2013 E) The amount of money college students spent in 2011 according to the formula to the left is $D billion. (Type an integer or a decimal.)