Array additions and averages - c

Question

So this weeks homework is to: 'Write a program that inputs 6 integers and puts them into an Array. The program
then prints out the following: A list of all Array elements, from 0 to 5 and the sum and
mean value of all elements. NB The mean value of the array elements will not
necessarily be an integer. In order to convert an integer into a real (float) use
casting:
To turn the integer ‘x’ into a float use float(x)
E.g.:
Average = float(sum)/number of elements ;
(In this case the number of elements is 6)'
Not quite sure what I am doing wrong here but my code seems to give back incorrect answers and I can't figure out why.
Any suggestions would be greatly appreciated. I feel like I am going to fail this module as I have struggled with it since the introduction of functions, etc.
Anyway, here is my code:
#include<stdio.h>
#include<conio.h>
#include<math.h>
int main() {
int numArr[5];
int i, sum = 0;
float avg;
printf("\nEnter 6 elements : \n");
for (i = 0; i < 6; i++)
scanf("%d", &numArr[i]);
for (i = 0; i < 6; i++) {
sum = sum + i;
}
avg = sum /6;
printf("The sum is : %d", sum);
printf("The mean value is : %f", avg);
return 0;
}

Answer 1

'Write a program that inputs 6 integers
int numArr[5];
^^^^^
Change this loop
for (i = 0; i < 6; i++) {
sum = sum + i;
}
like
for (i = 0; i < 6; i++) {
sum = sum + numArr[I];
}
And change this statement
avg = sum /6;
the following way
avg = ( float )sum /6;
And you forgot to output all elements of the array.
Take into account that according to the C Standard the function main without parameters shall be declared like
int main( void )
and you may remove header <math.h> because neither declaration is used from this header in your program.

Answer 2

Your array isn't large enough to hold 6 numbers.
Change
int numArr[5];
to
int numArr[6];
Currently, you are accessing the array out-of-bunds, resulting in undefined behaviour.
There are couple other problems too:
1) You are not summing the array elements
2) You are doing integer division
Fix it, it'd look like:
#include<stdio.h>
#include<math.h>
int main(void) {
int numArr[6];
int i, sum = 0;
float avg;
printf("\nEnter 6 elements : \n");
for (i = 0; i < 6; i++)
scanf("%d", &numArr[i]);
for (i = 0; i < 6; i++) {
sum = sum + numArr[i]; /* was summing `i` instead of numArr[i] */
}
avg = sum /6.0; /* was doing integer division */
printf("The sum is : %d", sum);
printf("The mean value is : %f", avg);
return 0;
}

Answer 3

sum = sum + i;
should be
sum = sum + numArr[i];
Array elements should be added.
Later
avg = sum/6.0

Answer 4

for (i = 0; i < 6; i++) {
sum = sum + numArr[i];
}
avg = (float)sum /6;
Notice numArr[i]

Answer 5

int numArr[5];
should be
int numArr[6];
and
for (i = 0; i < 6; i++) {
sum = sum + i;
}
should be
for (i = 0; i < 6; i++) {
sum = sum + numArr[i];
}
and
avg = sum /6;
should be
avg = sum/6.0 //because division of integer by an integer results by integer value. So we divide integer with a float (6.0) value