During One Period, the Average Price of a Gallon of Gasoline

Essay

During one period, the average price of a gallon of gasoline in a town changed from day to day. The table shows the average price, in dollars, for each of several consecutive days, where 0 represents Sunday, 1 represents Monday, and so on. Use the data points $(0,3.50),(2,3.15)$ , and $(4,3.6)$ to find a quadratic function defined by $f(x)=a x^{2}+b x+c$ that models the data. Graph $f$ together with the data.