The table shows the amounts A (in billions of dollars) budgeted for national defense for the years 1998 to 2004. (Source: U.S. Office of Management and Budget)
(a) Use a graphing utility to create a scatter plot of the data. Let t represent the year, with t = 8 corresponding to 1998.
(b) Use the regression feature of a graphing utility to find a quadratic model for the data.
(c) Use a graphing utility to graph the quadratic model with the scatter plot from part (a). Is the quadratic model a good fit for the data?
(d) Use the model to estimate the amounts budgeted for the years 2005 and 2010.
(e) Do you believe the model is useful for predicting the national defense budgets for years beyond 2004?