```
#include <stdarg.h>
#include <stdio.h>
/* this function will take the number of values to average
followed by all of the numbers to average */
double average ( int num, ... )
{
va_list arguments;
double sum = 0;
/* Initializing arguments to store all values after num */
va_start ( arguments, num );
/* Sum all the inputs; we still rely on the function caller to tell us how
* many there are */
for ( int x = 0; x < num; x++ )
{
sum += va_arg ( arguments, double );
}
va_end ( arguments ); // Cleans up the list
return sum / num;
}
int main()
{
/* this computes the average of 13.2, 22.3 and 4.5 (3 indicates the number of values to average) */
printf( "%f\n", average ( 3, 12.2, 22.3, 4.5 ) );
/* here it computes the average of the 5 values 3.3, 2.2, 1.1, 5.5 and 3.3
printf( "%f\n", average ( 5, 3.3, 2.2, 1.1, 5.5, 3.3 ) );
}
```