In this post students will be able to learn how to find the sum and average of first n natural number using C Programming Language.

#### Write a program to find sum and average of first n natural number.

##### Program:
``````#include<stdio.h>
int main(){
int n,i,sum=0;
float average;
printf("Enter a positive integer n: ");
scanf("%d", &n);

for (i = 1; i <= n; i++) {
sum += i;
}
average = (float)sum / n;
printf("The sum of the first %d natural numbers is %d\n", n, sum);
printf("The average of the first %d natural numbers is %.2f\n", n, average);
return 0;
}``````
##### Explaination:
1. The user is prompted to enter a positive integer n using the `printf()` function and the `scanf()` function is used to read the user input and store it in the variable `n`.
2. A variable called `sum` is initialized to 0.
3. A `for` loop is used to iterate from 1 to n (inclusive). For each iteration, the loop adds the current number (i) to the `sum` variable.
4. Once the loop is finished, the average is calculated by dividing the sum by n and storing the result in a variable called `average`. Note that we cast `sum` to a float before dividing by `n` to ensure that the result is a floating-point number.
5. The sum and average are printed to the console using the `printf()` function.