# Confusion about the definition of "Exponential Average"

I was having doubt regarding the concept of "exponential averaging". Till now I have come across the concept twice and they seem to be quite similar (except that they have minor but sharp differences, which sort of confuses me). Once in Operating System and another in Computer Networks.

The above picture is from Galvin OS text, which associates $$\alpha$$ (smoothening factor with the actual value , here actual CPU burst time).

The above picture is from Forouzan Computer Network text where the $$\alpha$$ is associated with the estimated value (of RTT).

The above picture is from Kurose and Ross Computer Networks text and it associates $$\alpha$$ with the actual value (of RTT) [ which is similar to what done in Galvin]

Is there any standard definition of this concept? It kind of seems confusing to me.