Percentages: The most useful statistics ever invented

"Genius is one percent inspiration and ninety-nine percent perspiration." - Thomas Edison Preface. You know what a percentage is. 2 out of 4 is 50%. 3 is 25% of 12. Etc. But do you know enough about percentages? Is a percentage the same thing as a fraction or a proportion? Should we take the difference between two percentages or their ratio? ................
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