calculo usando funcçoes media/variancia/desvio

# include<stdio.h>
# include<stdlib.h>
# include<math.h>
float media (int n,float *v);
float variancia (int n, float *v, float m);
main (void)
{
float m, s2, s;
float v[100];
int n;
int i;
printf("leitura tamanha da amostra\n");
do
{
printf ("digite o valor de n\n");
scanf("%d", &n);
}
while((n>100)||(n<2));
printf("leitura da amostra\n");
for( i=0; i<n; i++)
{
printf("digite valor\n");
scanf("%f", &v[i]);
}
for (i=0; i<n; i++)
{
printf("%f", v[i]);
}
printf("calculo da media\n");
m= media(n,v);
printf("calculo da variancia\n");
s2= variancia(n,v,m);
printf("calculo do desvio padrao\n");
s= sqrt(s2);
printf("media=%f, variancia=%f, desvio=%f", m, s2, s);
system ("pause");
return 0;
}


float media (int n, float *v)
{
float m=0.0;
int i;
for( i=0; i<n ; i++)
{
m= m +v[i];
}
m= m/n;
return m;
}

float variancia ( int n, float *v, float a)
{
float s2=0.0 ;
int i;
for (i=0; i<n; i++)
{
s2= s2 +(v[i]-a)*(v[i]-a);
}
s2=s2/(n-1);
return s2;
}