Hex to decimal find mean wrong result?

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

int HextoDec(char *hexArray); //function prototype
int calculateMean(int res1, int res2,int res3,int res4,int res5 );
int calculateStdDev(int res1, int res2,int res3,int res4,int res5, int var );
int calculateVariance(int res1, int res2,int res3,int res4,int res5,int mean );

main()
{

    char *hexnumber1 = "41226666";
    char *hexnumber2 = "41A0CCCD";
    char *hexnumber3 = "41574BC7";
    char *hexnumber4 = "4144CCCD";
    char *hexnumber5 = "4146E979";

    //Calling the conversion function
    int result1 = HextoDec(hexnumber1);
    int result2 = HextoDec(hexnumber2);
    int result3 = HextoDec(hexnumber3);
    int result4 = HextoDec(hexnumber4);
    int result5 = HextoDec(hexnumber5);


    printf("Calculating mean, std deviation and variance for the following hex numbers:\n\n 0x41226666 \n 0x41A0CCCD \n 0x41574BC7 \n 0x4144CCCD \n 0x4146E979\n\n");
    printf("Their respective decimal equivalent is: \n\n %i \n %i \n %i \n %i \n %i \n\n", result1, result2,result3,result4,result5);

    //calculating and printing out the mean of the decimal numbers
    int mean = calculateMean(result1,result2,result3,result4,result5);
    printf("Mean: %i \n", mean);


    //calculating and printing out the variance of the decimal numbers
    //int variance = calculateVariance(result1,result2,result3,result4,result5,mean);
    //printf("Variance: %i \n", variance);

    //calculating and printing out the standard deviation of the decimal numbers
    //int stdDev = calculateStdDev(result1,result2,result3,result4,result5, variance);
    //printf("Standard deviation: %i \n", stdDev);
}

//Converting the hex numbers into their decimal equivalent. Those values will then be used to
//calculate the mean, the standard deviation and the variance
int HextoDec(char *hexArray){

    int decimal;
    int bit;
    int i=0;
    int j=0;
    i = strlen(hexArray);

    //while there is a next bit in the array
    while(i!=0)
    {
    bit = hexArray[j];

    //if the bit is a digit do the following
    if(('0' <= bit && bit <= '9'))
    {
    decimal = decimal * 16;
    decimal = decimal + (bit - '0');
    }

    //if the bit is a letter do the following
    if(('A' <= bit && bit <= 'F'))
    {
    decimal = decimal * 16;
    decimal = decimal + (bit - '7');
    }

    i--;
    j++;

    }

    return decimal;
}


//Calculate the mean of the decimal values
int calculateMean(int res1, int res2,int res3,int res4,int res5 ){

    int meanresult =(res1+res2+res3+res4+res5)/5;
    
    return meanresult;
}


//Calculating the standard deviation
int calculateStdDev(int res1, int res2,int res3,int res4,int res5,int var ){

    int stdDevresult = sqrt(var);

    return stdDevresult;
}


//Calculating the variance
int calculateVariance(int res1, int res2,int res3,int res4,int res5, int mean ){

    int sum1 = (res1 - mean)*(res1 - mean);
    int sum2 = (res2 - mean)*(res2 - mean);
    int sum3 = (res3 - mean)*(res3 - mean);
    int sum4 = (res4 - mean)*(res4 - mean);
    int sum5 = (res5 - mean)*(res5 - mean);

    int vsum = sum1+sum2+sum3+sum4+sum5;

    int varresult = vsum/4;

    return varresult;
}

// main needs to return a value.  Your operating system needs to know.
// arrays are a programmer's friend.
// yes, different data type helps.  The 4 byte integer overflow prevented you from getting an answer anywhere near correct.
// This program still sux.

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

//Converting the hex numbers into their decimal equivalent. Those values will then be used to
//calculate the mean, the standard deviation and the variance
int HextoDec(char *hexArray) {
  int decimal;
  int bit;
  int i=0;
  int j=0;
  i = strlen(hexArray);
  while(i!=0) {
    bit = hexArray[j];
    //if the bit is a digit do the following
    if(('0' <= bit) && (bit <= '9')) {
      decimal = decimal * 16;
      decimal = decimal + (bit - '0');
    }

    //if the bit is a letter do the following
    if(('A' <= bit && bit <= 'F')) {
      decimal = decimal * 16;
      decimal = decimal + (bit - '7');
    }
    i--;
    j++;
  }
  printf("%d = 16b%s\n",decimal,hexArray);
  return decimal;
}


int calculateMean(float*a,int n) {
  int i;
  float sum = 0;
  for (i = 0; i < n; ++i)
    sum += a[i];
  return sum/n;
}

int calculateStdDev(int res1, int res2,int res3,int res4,int res5,int var ){
  int stdDevresult = sqrt(var);
  return stdDevresult;
}

int calculateVariance(int res1, int res2,int res3,int res4,int res5, int mean ){
  int sum1 = (res1 - mean)*(res1 - mean);
  int sum2 = (res2 - mean)*(res2 - mean);
  int sum3 = (res3 - mean)*(res3 - mean);
  int sum4 = (res4 - mean)*(res4 - mean);
  int sum5 = (res5 - mean)*(res5 - mean);
  int vsum = sum1+sum2+sum3+sum4+sum5;
  int varresult = vsum/4;
  return varresult;
}

main() {
  char *hexnumber1 = "41226666";
  char *hexnumber2 = "41A0CCCD";
  char *hexnumber3 = "41574BC7";
  char *hexnumber4 = "4144CCCD";
  char *hexnumber5 = "4146E979";
  int result1 = HextoDec(hexnumber1);
  int result2 = HextoDec(hexnumber2);
  int result3 = HextoDec(hexnumber3);
  int result4 = HextoDec(hexnumber4);
  int result5 = HextoDec(hexnumber5);

  float array[300];
  int i=0;
  array[i++] = result1;
  array[i++] = result2;
  array[i++] = result3;
  array[i++] = result4;
  array[i++] = result5;

  printf("Calculating mean, std deviation and variance for the following hex numbers:\n\n 0x41226666 \n 0x41A0CCCD \n 0x41574BC7 \n 0x4144CCCD \n 0x4146E979\n\n");
  printf("Their respective decimal equivalent is: \n\n %i \n %i \n %i \n %i \n %i \n\n", result1, result2,result3,result4,result5);

  //calculating and printing out the mean of the decimal numbers
  float mean = calculateMean(array,i);
  printf("Mean: %g\n", mean);


  //calculating and printing out the variance of the decimal numbers
  //int variance = calculateVariance(result1,result2,result3,result4,result5,mean);
  //printf("Variance: %i \n", variance);

  //calculating and printing out the standard deviation of the decimal numbers
  //int stdDev = calculateStdDev(result1,result2,result3,result4,result5, variance);
  //printf("Standard deviation: %i \n", stdDev);
  return 0;
}