You assigned floating points A = 2.0, B = 5.0, C = 7.0, D =11.0;

But all your definitions are defined as shaping int a, b, c, d and average.

Then output with "%f"

replace

{

Floating a, b, c, d, average;

a=2.0，b=5.0，c=7.0，d = 1 1.0；

Average value = (a+b+c+d)/4.0;

Printf("%f ",average);

The answer to this program is 6.