Calculating average miles walked per day with while loop - c

Question

I am unable to get the input to be added and get the correct output for the average.
The code below is as far as I have made it. Any help would be greatly appreciated!
#include <stdio.h>
int main() {
/* variable definition: */
int days;
float avg, miles;
/* Initialize */
days=1;
// Loop through to input values
while(days<=7) {
printf("Enter the number of miles for each day walked.");
// use %lf for double, %f for float
scanf("%f", &miles);
days++;
}
avg = miles / days;
printf("average is %f\n " , avg );
return 0;
} // end main

Answer 1

As John3136 said, you aren't keeping track of the total miles walked. You scan in miles, but you don't keep track of the sum of the miles. Your average is simply your last entered miles divided by 7.
Here is a proposed solution:
int main(void)
{
// variable definition
int days = 0;
float avg = 0, miles = 0;
// Loop through to input values
while(days < 7)
{
printf("Enter the number of miles for each day walked: ");
scanf("%f", &miles);
avg += miles;
days++;
}
avg /= days;
printf("average is %.2f\n " , avg);
return 0;
}
With help from Jonathan Leffler here is an enhanced version of the previous code:
#include <stdio.h>
int main(void)
{
// variable definition
int days = 0;
double miles = 0.0, total_miles = 0.0;
// Loop through to input values
while(days < 7)
{
printf("Enter the number of miles for day %d: ", days + 1);
if(!scanf("%lf", &miles))
return -1;
total_miles += miles;
days++;
}
printf("Total miles: %.2lf / %d Days = %.2lf Average miles per day.\n",
total_miles, days, (days > 0) ? total_miles / days : 0.0);
return 0;
}