Array : Meand & Standard Deviations

/* This program computes the meand and standard deviations of 
the values inside an array */
#include <stdio.h>
#include <math.h>
#define MAX 5

int 
main (void)
{

	double mean, sd, sum, sumsq;
	double x[] = {10.0, 15.0, 20.0, 10.0, 30.0};
	int i;

	sum = 0;
	sumsq = 0;

	/* computing the sum and sum of squares */
	for (i=0; i<MAX; ++i)
	{
		sum = sum + x[i];
		sumsq = sumsq + x[i] * x[i];
	}


	/* computing mean and standard deviation */
	mean = sum / MAX;
	sd = sqrt(sumsq / MAX - mean * mean);


	/* printing report */
	printf ("The mean is %lf. \n", mean);
	printf ("The standard deviation is %lf. \n", sd);
	
	return (0);
}