Ensemble Average

For a Statistical Ensemble, the percentage of systems in a particular microstate is the Probability for that microstate.

If we do a million two-coin flips, close to 250,000 of them will be heads-heads. We say the probability is 0.25 for the heads-heads microstate.

Appendix A

We frequently find that the mathematicians and physicists prefer to use numbers for probability such that the value for “everything” or “all” is 1 rather than 100%.