The average energy is a source-bound weighted sum. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.
Average energy uses the weighted numerator
The checked numerator is eight joules.
E n u m = 8 J E_{\rm num}=8\ {\rm J} E num = 8 J
Weighted energy numerator The numerator is recomputed from energies and weights. states=s0:0J,w=4|s1:2J,w=2|s2:4J,w=1 zTotal=7 probabilities=s0:4/7=4/7|s1:2/7=2/7|s2:1/7=1/7 energyNumerator=8 J averageEnergy=8/7 J weightOrigin=explicit integer weights
The average divides by the partition total
The average energy is eight sevenths of a joule.
⟨ E ⟩ = 8 7 J \langle E\rangle=\frac{8}{7}\ {\rm J} ⟨ E ⟩ = 7 8 J
Average energy The average-energy label cannot drift. states=s0:0J,w=4|s1:2J,w=2|s2:4J,w=1 zTotal=7 probabilities=s0:4/7=4/7|s1:2/7=2/7|s2:1/7=1/7 energyNumerator=8 J averageEnergy=8/7 J weightOrigin=explicit integer weights