How do I calculate average in c++?

Question

(average does not work)

#include <iostream>
using namespace std;

double inflationRate (float old_cpi, float new_cpi);

int main()
{
float old_cpi, new_cpi;
double sum, average;

cout << "Enter the old and new consumer price indices: ";
cin >> old_cpi >> new_cpi;

cout << "Inflation rate is " << inflationRate(old_cpi, new_cpi) << endl;

sum += inflationRate;

average = sum/inflationRtae;

cout << average << endl;

return 0;
}

double inflationRate(float old_cpi, float new_cpi)
{
return ((new_cpi - old_cpi) / old_cpi * 100);
}

Answer 1

Sum is uninitialized, which leads to compilation error and the value of average becoming unpredictable.

// Init sum
double sum = 0

Also, there's only 1 inflation rate, so dividing average by whatever value is unnecessary.

Declare a counter, for every time you get input from the user, increment counter. To compute average, divide it by counter.