can someone can help me? modify to modify this code using an for loop? thanks

If all the values are stored in the same array of length arraylength then this will work

int average = 0;
     for(int i = 0; i<arraylength; i++) {
          average += array[i];
     average /= arraylength;

bool answer = true..

const int arraylength = 5;
int array[arraylength]={1,3,5,2,4};

//...mrboolf code

Do you mean that you have four separate arrays, and you're trying to find the average across them?

If so, enclose your code inside a loop, controlled by variable "counter"

One correction, to get the average

average= ( a[counter]+b[counter]+c[counter]+d[counter] ) / 12;

enclose the addition in parentheses so all the values are added, then the division occurs. As you wrote it, d[counter] was divided by 12, then added to the other three values.