please write solution using C++ program.

Using Array to calculate the average of 5 grades:

1. read grade from user input.

2. read grades from the file.

// Hint:

const int ISIZE = 5, sales[ISIZE];

ifstream dataFile;

datafile.open("sales.dat");

if (!dataFile)

cout << "Error opening data file ";

else

{ // Input daily sales

for (int day = 0; day < ISIZE; day++)

dataFile >> sales[day];

dataFile.close();

}