Program to Find Sum and Average of Three Real Numbers 

#include <stdio.h>

main()

{

float a, b, c, sum, avg;

printf("\nEnter value of three numbers: ");

scanf("%f %f %f", &a, &b, &c);

sum = a + b + c;

avg = sum / 3;

printf("\nSum = %.2f", sum);

printf("\nAverage = %.2f", avg);

getch();

}