Thread: another exam question

This another question that will be placed on the exam but with a different layout. Give it a try... I have others that I'm considering.
Give me your answer and opinion (fair or not fair) for a beginner learning C. Thanks for your help!

The following function supposedly computes the sum and average of the numbers in the array a, which has the length n. avg and sum point to variables that the function should modify. Unfortunately, the function contains several error; find and correct them.

Code:

void avg_sum(float a[], int n, float *avg, float *sum)
{
int i;

sum = 0.0;

for(i = 0; i < n; i++);
     sum += a[i];
avg = sum / n;

}