Given the following program fragment: int main() \& double currDol, pastDol; int pastYr, currYr; // (not all lines shown) currDol = TocurrDollars (pastDol, pastYr, currYr); // (not all lines shown) return 0 ; double TocurrDollars (double pastDol, int pastYr, int currYr) double answer; // (not all lines shown) return answer; What is the function declaration you should add to the top of the file before main to make this work? (Single line answer only)