#include <stdio.h> // This function returns a letter grade based on the average char gradeFunction(double avg) { if (avg >= 90) return 'A'; else if (avg >= 80) return 'B'; else if (avg >= 70) return 'C'; else if (avg >= 60) return 'D'; else return 'F'; } int main(void) { int count; double sum = 0, grade; // Ask the user to enter total grades between 1 to 5 printf("How many grades (1 to 5)? "); scanf("%d", &count); // Validate that count is between 1 and 5 if (count < 1 || count > 5) { printf("Invalid number. You must enter between 1 and 5 grades.\n"); return 1; // Exit } // Loop to collect each grade for (int i = 1; i <= count; i++) { printf("Enter grade %d: ", i); scanf("%lf", &grade); sum += grade; } // Calculate the average score double avg = sum / count; // Display numeric average printf("Average: %.2f\n", avg); // Display letter grade printf("Letter grade: %c\n", gradeFunction(avg)); return 0; }