Calculating the mean of part of an array - c

Question

I am trying to calculate the mean of high and low temperatures entered by a user and the number of days that can be included are between 1 and 4 however, I'm having difficulty understanding how to go about this. The code I wrote yields a completely irrelevant number. Here's my code:
#include <stdio.h>
int main (void)
{
int i;
int limit;
int day[] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
int high[10],low[10];
printf("---===IPC Temperature Analyzer V2.0===---\n");
printf("Please enter the number of days between 3 and 10, inclusive: ");
scanf("%d", &limit);
while (limit <= 2 || limit >= 11) {
printf("Invalid entry, please enter a number between 3 and 10, inclusive: ");
scanf("%d", &limit);
}
for(i = 0;i < limit; i++) {
printf("Day %d - High: ", day[i]);
scanf("%d", &high[i]);
printf("Day %d - Low: ", day[i]);
scanf("%d", &low[i]);
}
printf("\nDay Hi Low\n");
for (i = 0; i < limit; i++) {
printf("%d %d %d\n", day[i], high[i], low[i]);
}
int max = 0;
int min = 0;
for (i = 0; i < limit; i++) {
if (high[max] < high[i])
max = i;
if (low[min] < low[i])
min = i;
}
printf("\nHighest temperature was: %d on day %d", high[max], day[max]);
printf("\nLowest temperature was: %d on day %d ", low[min], day[min]);
int n;
int avg = high[i] + low[i]/i;
printf("\nEnter a number between 1 and 4 to see the average temperature for the entered number of days, enter a negative number to exit\n");
scanf("%d", &n);
while (n > 4) {
printf("Invalid entry, please enter a number between 1 and 4, inclusive: ");
scanf("%d", &n);
}
while (n < 0) {
printf("Goodbye!\n");
exit(0);
}
for (i = 0; i < n; i++) {
printf ("The average temperature up to day %d is: %d", day[i], avg);
}
return 0;
}

Answer 1

I suppose you misplaced expression int avg = high[i] + low[i]/i, and also the meaning does not seem correct to me:
First: I suppose you want to print the average for each particular day in the loop i : 0..n-1, but you calculate the value only once outside the loop (and you may think of what i at your place means.
Second: You have only two values for each day, i.e. high and low, and not i values, right? So to get the average temperature for a particular day it should be avg = (high[i] + low[i])/2. Also note the braces, which yields a different operator precedence than in your code. And if you want to calculate an "overal" avg up to a particular day, I'd make the formula explicit, e.g. by distinguishing an averageOfDay from an overallAverage.
Third: are you sure avg should be an int? I'd suggest to use float.
float avgSum = 0.0;
for (i = 0; i < n; i++) {
float avgOfDay = (high[i] + low[i])/2.0;
avgSum += avgOfDay;
}
float overallAvg = avgSum/n;
printf ("The average temperature up to day %d is: %f", day[n-1], overallAvg);