C++: interestEarned coming back wrong - c++

Question

I'm learning C++ and this is an assignment I have to do, it's complete but my interestEarned is not coming back correctly but the bankBalance is correct so I'm just not displaying interestEarned correctly. "Total Interest Earned: $65.50" is incorrect is supposed to display "$120.50" as my teacher said. What am I doing wrong?
Here is my code:
#include <iostream>
#include <iomanip>
using namespace std;
int main() {
// Variables
int numOfCustomers, numOfMonths = 0;
double bankBalance, depositAmount, withdrawnAmount, interestRate, interestEarned = 0.0;
const int MIN = 0;
// Asking for Number of Customers
cout << "Enter the number of customers: ";
cin >> numOfCustomers;
// Making sure the input was not 0 or lower
while (numOfCustomers <= MIN) {
cout << "==>Number of customers must be at least 1. Try again: ";
cin >> numOfCustomers;
}
// Validating each Customer
for (int c = 1; c < (numOfCustomers + 1); c++) {
// Start of each Customer
cout << "\nCUSTOMER " << c << ":\n";
// Asking for Number of Months --
cout << "Enter the number of months the account has been opened: ";
cin >> numOfMonths;
// Making sure the input was not 0 or lower
while (numOfMonths <= MIN) {
cout << "==>Number of months must be at least 1. Try again: ";
cin >> numOfMonths;
}
// Asking for Starting Balance --
cout << "Enter the starting balance: $";
cin >> bankBalance;
// Making sure the input was not 0 or lower
while (bankBalance < MIN) {
cout << "==>Starting balance can't be negative. Try again: $";
cin >> bankBalance;
}
// Asking for Monthly Interest Rate --
cout << "Enter the monthly interest rate as a decimal (i.e. 0.05 = 5%): ";
cin >> interestRate;
// Making sure the input was not 0 or lower
while (interestRate < MIN) {
cout << "==>Monthly interest rate can't be a nagative. Try again: ";
cin >> interestRate;
}
// Validating each Month
for (int m = 1; m < (numOfMonths + 1); m++) {
// Deposit Amount
cout << "\nEnter deposit amount for Month " << m << ": $";
cin >> depositAmount;
bankBalance = bankBalance + depositAmount;
// Withdrawn Amount
cout << "Enter withdrawn amount for Month " << m << ": $";
cin >> withdrawnAmount;
bankBalance = bankBalance - withdrawnAmount;
// Calculating Interest Earned
interestEarned = bankBalance * interestRate;
// Complete bankBalance
bankBalance = bankBalance + interestEarned;
}
// Account Summary
cout << "\nACCOUNT SUMMARY" << endl;
cout << fixed << setprecision(2);
cout << "Number Months Active: " << numOfMonths << endl;
cout << "Ending Balance: $" << bankBalance << endl;
cout << "Total Interest Earned: $" << interestEarned << endl;
}
system("pause");
return 0;
}

Answer 1

Use another variable that is initialized to zero before the loop. In the loop, add the value of interestEarned to it. - #Peter