Output:
Exer6

#include

#include

float grade, average, items, sum;

void main(){

clrscr();

average=0;

sum=0;

do{printf("Enter grade (-1 to exit): ");

scanf("%f", &grade);

if((grade!=-1)&&(grade<=100)) { items++; sum=sum+grade; } }while(grade!=-1); average=sum/items; printf("Class Average: %.2f\n", average); if((average>=95)&&(average<=100)) { printf("Rating: A"); } else if((average>=90)&&(average<=94)) { printf("Rating: B"); } else if((average>=85)&&(average<=89)) { printf("Rating: C"); } else if((average>=80)&&(average<=84)) { printf("Rating: D"); } else if((average>=75)&&(average<=79)) { printf("Rating: E"); } else if(average<=74) { printf("Rating: FAILED"); }

getch();

}