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- Rounding Percentages 1 answer
This problem arose while tallying votes in a poll and displaying the results as a whole number percentage. So if "Option A" received $300$ votes and "Option B" received $100$, the display should read "$75\%$, $25\%$".
There is a requirement that the integer percentages must add up to $100\%$. Which means that rounding up one percentage will cause the other to round down.
How should the following percentages be rounded?
- $20.5\%$ & $79.5\%$ (which one rounds up?)
- $49.5\%$ & $50.5\%$ (equal or not?)
- $0.5\%$ & $99.5\%$ (is $0.5\%$ statistically significant?)
I tend to feel that the small numbers should be given more priority (so $0.5\%$ rounds up to $1$, while the $1\%$ difference in the $49.5$/$50.5$ split gets increased to $2\%$ giving $49$/$51$).
Is there any "one rule to round them all"?