Answer:
#include<iostream>
int main() {
float num_1, num_2, num_3, num_4, average;
//Taking input for four numbers
std::cout << "Enter first number(integer or floating-point)";
std::cin >> num_1;
std::cout << "Enter second number(integer or floating-point)";
std::cin >> num_2;
std::cout << "Enter third number(integer or floating-point)";
std::cin >> num_3;
std::cout << "Enter fourth number(integer or floating-point)";
std::cin >> num_4;
average= (num_1+num_2+num_3)/3;
// Comparing average with fourth number
if (average==num_4)
{
std::cout << "Equal";
}
return 0;
}