Day 10 of Programming in C

Write a function to input random values in 2 array and now find their mean and standard deviation using another functions.

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <math.h>
void rand_100(int *arr, int n);
float mean(int *arr, int n);
float std(int *arr, int n);
void main()
{
    srand(time(NULL));
    int a[100], b[200];
    rand_100(a, 100);
    rand_100(b, 200);
    printf("First Array\nMean = %f\nStandard Deviation = %f\n\n", mean(a, 100), std(a, 100));
    printf("Second Array\nMean = %f\nStandard Deviation = %f", mean(b, 200), std(b, 200));
}
void rand_100(int *arr, int n)
{
    for (int i = 0; i < n; i++)
    {
        arr[i] = rand() % 101;
    }
}
float mean(int *arr, int n)
{
    float sum = 0;
    for (int i = 0; i < n; i++)
    {
        sum += arr[i];
    }
    return sum / n;
}
float std(int *arr, int n)
{
    float std = 0, m = mean(arr, n);
    for (int i = 0; i < n; i++)
    {
        std += pow(arr[i] - m, 2);
    }
    return sqrt(std / n);
}