Why is the average for my array of numbers not correct?

I have written a method to take an array (via pointer) and its size to calculate the average. I am still relatively new to pointers. I have tried to remove the reference operator all throughout the code to the point at which it will compile, but the values returning are not intended. For instance, if I pass in an array size of 3, and then my array values are 1, 2, 3, with my eyes closed I can tell you that that average should be 2. However my code returns 2.666666667. Thinking in reverse, I multiplied 2.6666...7 by 3, which equals 8. This leads me to think that I somewhere, a 2 is getting amended to the array, like 1,2,3,2, however I'm unsure at this point. If anyone has any experience with pointers/simple arithmetic I'd appreciate your advice, because again, I am new to pointers and this idea of reference by address. Thanks!

double *Average(double *arr, int size)

double *avg;
avg = (double *)malloc(sizeof(double));

*avg = 0;

int i;
for (i = 0; i < size; i++)

*avg = *avg + arr[i];


*avg = *avg / (double) size;

printf("The average of the array: %fn", *avg);
return avg;



How the method gets called from main:

else if (choice == 'C' || choice == 'c')

int count;

printf("How many numbers do you want to use in the array?n> ");
scanf("%d", &count);

double *arr;
arr = (double *)malloc(sizeof(double) * count);

int i;
for (i = 0; i < count; i++)


printf("Please enter a number (%d of %d)n> ", i + 1, count);
scanf("%lf", &arr[i]);


Min(arr, count);

Max(arr, count);

Average(arr, count);



Tests:

Expected: 3, Got: 4.333333

Expected: 1, Got: 1

Expected: 5, Got: 5.888889

Two extra methods per user request:

double *Min(double *arr, int size)

double *min = &arr[0];
int i;
for (int i = 1; i < size; i++)

if (arr[i] < *min)

*min = arr[i];



printf("Smallest number in array: %fn", *min);
return min;


double *Max(double *arr, int size)

double *max = &arr[0];
int i;
for (int i = 1; i < size; i++)

if (arr[i] > *max)

*max = arr[i];



printf("Largest number in array: %fn", *max);
return max;



Average(1, 3, 5, 3)

Min

Max

Average

double

double*

avg

double

Average

min

max

const double*

1 Answer
1

Problem is here, correct this one:

*max = arr[i];


you're changing the *max which is arr[0] to the max or min of your array. So when Average() function gets the array, it's not the array you've input, it's changed. For example:

*max

arr[0]

Average()

Max(1,3,5)=5


array becomes:

arr=5,3,5


It's average correctly is:

Average(5,3,5 = 4.3333


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