Total personal income of the country (in billions of dollars) for selected years from 1958 to 2003 is given in the table. Year Personal Income 1958 412.8 1968 832.7 (a) These data can be modeled by an exponential function. Write the equation of this function, with x as the number of years after 1958 1978 2305.9 1988 4878.7 (b) If this model is accurate, what will be the country's total personal income in 2008? (c) In what year does the model predict the total personal income will reach $22 trillion? 1998 8423.9 2003 10,233.8