See https://en.wikipedia.org/wiki/Odds_ratio https://en.wikipedia.org/wiki/Odds_ratio for one answer. Another "single number" answer is generated by the class

See https://en.wikipedia.org/wiki/Odds_ratio https://en.wikipedia.org/wiki/Odds_ratio for one answer. Another "single number" answer is generated by the class of tests that determine the statistical significance of an observation; see https://en.wikipedia.org/wiki/Alpha_level https://en.wikipedia.org/wiki/Alpha_level for more about this. There are many other ways to accomplish what you're talking about. The biggest problem with your made-up examples is that they are just cases of "bad reporting."