Task 4a:  After the completion of task 1 and 2 write the code for the Distance function with input parameters for the indexes of two cities, Index1 and Index2, as type integer, and returns the distance in miles between the two cities as type Double. Use the functions CoordinateToDegrees and DegreesToRadians to convert the latitudes and longitudes in Hubs for Index1 and Index2 to radians for the calculation. The stub for this function has been provided.