"inf" was displayed at runtime

#include<stdio.h>
/* Enter element number size real number array a in order */
void readDoubleArray (double a[], int size)
{
    inti;
    for(i=0;i<size;i=i+1){
        printf("%dth?", i+1);
        scanf("%lf", & a[i]);
    }
}

/* Output real number array a of element number size in order */
void printDoubleArray (double a[], int size)
{
    inti;
    for(i=0;i<size;i=i+1){
        printf("%f", a[i]);
    }
    printf("\n");

}

/* Store the mean of the real number array a of the number of elements size in *ave and the variance in *var*/
voidave_var_double_array(double a[], int size, double*ave, double*var, double*hyoujunnhennsa, double*hennisati)
{
    inti;
    double sum = 0.0, dsum = 0.0;
    for(i=0;i<size;i=i+1){
        sum = sum + a[i]; 
       *ave=sum/size;
    }
    for(i=0;i<size;i=i+1){
        dsum=dsum+(a[i]-*ave)*(a[i]-*ave); 
       *var=dsum/size;
    }for(i=0;i<size;i=i+1){
        *var=(*hyoujunnhennsa)*(*hyoujunnhennsa);
        *hensati=((10*(a[i]-*ave))/(*hyoujunnhennsa))+50;
    }    
}


int main (void)
{
    double a[100], ave, var, hyoujunnhennsa, hennsati;
    int num;
     
    printf("Number of data? ");
    scanf("%d", & num);

    readDoubleArray(a,num);
    
    ave_var_double_array(a, num, & ave, & var, & hyoujunnhennsa, & hennsati);
 
    printf("Score:");
    printDoubleArray(a,num);
    printf("Deviation value: %.1f\n", hensati);

    return 0;
}

$./a.out
Number of data?5
Number one? 40
Second? 56
Third?92
4th? 78
Number five? 67
Score: 40.00000056.000092.000078.000067.000000 
Deviation value: inf