问试图从4名学生(由用户输入定义)中找出平均3次测验成绩，但我不知道哪里出了问题(下面的代码)。

EN

#include <stdio.h>
#define NUM_STUDENTS 4
#define NUM_QUIZZES 3

int main() {


//beginning of part 2 code
    int arr_grades[NUM_STUDENTS][NUM_QUIZZES];
    int st_val, students, quizzes;
//introduce the program
    printf("\n\nHello Professor, and welcome to the grading portal.\n\n");

    for (students = 0; students < NUM_STUDENTS; students++) {
        //this allows the entry of three quiz grades per student to be stored
        printf("Please enter 3 quiz grades for student %d: ", students+1);
        for (quizzes = 0; quizzes < NUM_QUIZZES; quizzes++)
            scanf("%d", &arr_grades[students][quizzes]);
    }
//here we will be getting the average of our inputs
    printf("\nAverage Quiz Grades\n");
    for (students = 0; students < NUM_STUDENTS; students++) {
        printf("Student %d's average is: ", students+1);
        //initialize
        st_val = 0;
        //this is the next look that will mimic the same for quizzes then provide       us with the final result
        for (quizzes = 0; quizzes < NUM_QUIZZES; quizzes++)
            st_val += arr_grades[students][quizzes];
            printf("%3d\n", st_val / NUM_STUDENTS);
}

Please enter 3 grades for student 1:  10 10 10
Please enter 3 grades for student 2:  2 0 1
Please enter 3 grades for student 3:  8 6 9
Please enter 3 grades for student 4:  8 4 10

    Average Quiz Grades
Student 1's Average is:   7
Student 2's Average is:   0
Student 3's Average is:   5
Student 4's Average is:   5

    Average Quiz Grades
Student 1's Average is:   10.0
Student 2's Average is:   1.0
Student 3's Average is:   7.7
Student 4's Average is:   7.3