C language: Calculate the average value and standard deviation of data in an array

/*
Example: calculate the average and standard deviation in C language
*/

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>

void The_Average(float *tab, int *length){
	float sum=0,sum2=0;
	for(int i=0;i<*length;i++){
		sum+=tab[i];
	}
	sum /=  *length;
	printf("average : %.2f",sum);
	float tab2[*length],tab3[*length];
	for(int i=0;i<*length;i++){
		tab2[i]=tab[i]-sum;
		tab3[i]=pow(tab2[i],2);
		sum2+=tab3[i];
	}
	float result= sqrt(sum2 / (*length-1));
	printf("\nstandard deviation : %.2f",result);
}

int main(int argc, char const *argv[]) {

	float array[] = {0,1.0,2,3,4,6,9,12};
    int length = sizeof(array)/sizeof(float);
	The_Average(array,&length);
   return 0;
}