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A comment on Dyson air purifier outperformed by cheap DIY box fan filter in Marketplace test. Parent comment

Re:Dyson air purifier outperformed by cheap DIY box fan filt... by ortusdux on Thursday February 11, 2021 @11:26AM (#26103435)
I rounded up to be generous.
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Re:Dyson air purifier outperformed by cheap DIY box fan filt... by renerthr on Thursday February 11, 2021 @02:52PM (#26106252)
1. I concluded that's what you did, but found it a bit annoying. 100x15/16=93.75 . I find it unnecessarily confusing (as the parent commenter probably did) to round it to 93, when the correct rounding is 94.

2. The article says "15x more", so the right math would be 100x16/17=94.12 .

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Re:Dyson air purifier outperformed by cheap DIY box fan filt... by ortusdux on Thursday February 11, 2021 @03:20PM (#26106592)
This is exactly the kind of pedantry I was trying to avoid by rounding.

Fan X moves "15x more" air than fan Y. For every 1 unit of air fan X moves, Y will move 1x15 = 15 units. In the time it takes fan Y to move 100 units of air, fan X will move 100*(1/15) units, or 6 2/3rds units. 6.666... rounds to 7.

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