C Program to Calculate Average of Numbers

We can explain C program to calculate the average of set of N numbers step by step.

The variable number is declared as float and therefore it can take both integer and real numbers. Since the symbolic constant N is assigned the value of 10 using the #define statement, the program accepts ten values and calculates their sum using the while loop. The variable count counts the number of values and as soon as it becomes 11, the while loop is exited and then the average is calculated.

To understand and execute easily for this program, user must need to have knowledge of following C Programming Concepts:

• C for loop with Example
• C While Loop with Example

Source Code

#define N 10 /* SYMBOLIC CONSTANT */
main()
{
int count ; /* Declaration of  */
float sum, average, number ; /* Variables */
sum = 0 ; /* Initilization */
count = 0 ; /* Of Varibales */
while( count < N )
{
scanf("%f", &number) ;
sum = sum + number ;
count = count + 1 ;
}
average = sum/N ;
printf("N = %d Sum = %f", N, sum);
printf(" Average = %f", average);
}

Output

1
2.3
4.67
1.42
7
3.67
4.08
2.2
4.25
8.21
N = 10 Sum = 38.799999 Average = 3.880000

Notice that the actual value of sum is 38.8 but the value displayed is 38.799999. In fact, the actual value that is displayed is quite dependent on the computer system. Such an inaccuracy is due to the way the floating point numbers are internally represented inside the computer.