-nan(ind) and not showing sentinel in .txt?

[nadouglas1]

When I start the program and enter 0 as an account number my average gives me -nan(ind). Is there a way to hide this and have it display "No Data"? Also, this program writes to a .txt and I wanted to know if there was a way to not display the sentinel in the .txt.

// Determines a customer's bill for a local cable company

#include <iostream>
#include <iomanip>
#include <string>
#include <fstream>
#include <cstdlib>
using namespace std;



int main()
{
	int account_Number;
	int basic_Service;
	int premium_Channels;
	double amount_Due;
	char customer_Type;
	int basic_Connections;
	const double RESIDENTIAL_PROCESSING_FEE = 4.50;
	const double RESIDENTIAL_BASIC_FEE = 20.50;
	const double BUSINESS_PROCESSING_FEE = 15.00;
	const double RESIDENTIAL_PREMIUM_PER_CHANNEL = 7.50;
	const double BUSINESS_PREMIUM_PER_CHANNEL = 50.00;
	const double BUSINESS_BASIC_FEE = 75.00;
	const double BUSINESS_ADDITIONAL_CONNECTION = 5.00;
	int business_Customer = 0;
	int residential_Customer = 0;
	int count = 0;
	double residential_Total = 0;
	double average = 0;
	double business_Total = 0;
	double total;



	cout << "This program computes a cable bill." << endl << endl;

	cout << fixed << showpoint << setprecision(2);

	ofstream outputFile; 
	outputFile.open("BillingReport.txt");

	outputFile << fixed << showpoint << setprecision(2);

	cout << "Enter account number <an integer>: ";
	cin >> account_Number;

	outputFile << "Account number: " << account_Number << endl;

	while (account_Number != 0)
	{
		cout << "Enter customer type: R or r (Residential), B or b (Business):  ";
		cin >> customer_Type;
		cout << endl;
		switch (customer_Type)
		{
		case 'b':
		case 'B':
			cout << "Enter the number of basic service connections: ";
			cin >> basic_Connections;

			cout << "Enter the number of premium channels: ";
			cin >> premium_Channels;
			cout << endl;

			cout << "Account number: " << account_Number << endl;

			if (basic_Connections <= 10)
			{
				amount_Due = BUSINESS_PROCESSING_FEE + BUSINESS_BASIC_FEE + premium_Channels * BUSINESS_PREMIUM_PER_CHANNEL;
			}
			else
			amount_Due = BUSINESS_PROCESSING_FEE + BUSINESS_BASIC_FEE + (basic_Connections - 10) * BUSINESS_ADDITIONAL_CONNECTION + premium_Channels * BUSINESS_PREMIUM_PER_CHANNEL;

			cout << "Amount Due: " << amount_Due;
			cout << endl << endl;

			outputFile << "Amount due: " << "$" << amount_Due << endl << endl;

			business_Customer++;
			business_Total += amount_Due;
			count++;

			break;

		case 'r':
		case 'R':
			cout << "Enter the number of premium channels: ";
			cin >> premium_Channels;
			cout << endl;

			cout << "Account number: " << account_Number;
			cout << endl;

			amount_Due = (RESIDENTIAL_PROCESSING_FEE + RESIDENTIAL_BASIC_FEE)
				+ premium_Channels * RESIDENTIAL_PREMIUM_PER_CHANNEL;

			cout << "Amount Due: " << amount_Due;
			cout << endl << endl;

			outputFile << "Amount due: " << "$" << amount_Due << endl << endl;

			residential_Customer++;
			count++;
			residential_Total += amount_Due;

			break;

		default:
			cout << "Invalid customer type." << endl << endl;
		}

		cout << "Enter account number <an integer>: ";
		cin >> account_Number;

		outputFile << "Account number: " << account_Number << endl;
	}

	cout << endl;
	total = (residential_Total + business_Total) / count;

	cout << left << setw(35) << "Number of residential customers: " << residential_Customer << endl;
	outputFile << endl << left << setw(35) << "Number of residential customers: " << residential_Customer << endl;

	cout << left << setw(35) << "Total residential customer bill: "  << "$" << residential_Total << endl;
	outputFile << left << setw(35) << "Total residential customer bill: " << "$" << residential_Total << endl;

	cout << left << setw(35) << "Number of business customers: " << right << business_Customer << endl;
	outputFile << left << setw(35) << "Number of business customers: " << business_Customer << endl;

	cout << left << setw(35) << "Total business customer bill: " << "$" << business_Total << endl;
	outputFile << left << setw(35) << "Total business customer bill: " << "$" << business_Total << endl;
	
	cout << left << setw(35) << "Average bill: " << "$" << total << endl << endl;
	outputFile << left << setw(35) << "Average bill: " << "$" << total << endl;

	outputFile.close();
	return 0;
}