A finite weighted ensemble has one checked normalizing total. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.

highlighted = computed this step

One partition total normalizes every row

The explicit weights add to seven.

Z=4+2+1=7Z=4+2+1=7
Partition totalThe total weight is computed from the rows.states=s0:0J,w=4|s1:2J,w=2|s2:4J,w=1zTotal=7probabilities=s0:4/7=4/7|s1:2/7=2/7|s2:1/7=1/7energyNumerator=8 JaverageEnergy=8/7 JweightOrigin=explicit integer weights

Each probability uses the same total

The three probabilities share that one total.

47,27,17\frac{4}{7},\quad\frac{2}{7},\quad\frac{1}{7}
Normalized weightsEvery probability label is source-bound.states=s0:0J,w=4|s1:2J,w=2|s2:4J,w=1zTotal=7probabilities=s0:4/7=4/7|s1:2/7=2/7|s2:1/7=1/7energyNumerator=8 JaverageEnergy=8/7 JweightOrigin=explicit integer weights