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Comment by traceroute66 | Hacker News Reader

Rant time.... ;-)

What's with these stupid "X in Y" numeric expressions that the dumb media insist on continuing to heap on the world ?

Why not consistently use a standardised means of comparison.

Like, I don't know .... percent. Or "X in 100" if you think your newspaper/blog/website readership are too dumb to know what the % symbol means. The clue's in the name FFS ... per... cent ... that's what its there for !

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I generally agree with your sentiment, but not in this case. They're doing it here because fractional humans don't exist in real life, and the measure isn't being used for comparison.

"1 in 153 people" is easier for the human mind to visualize than "0.65 out of every 100 people."

Ratios and fractions are covered in (hopefully?) every grade school, usually right along side percentages. They're an entirely valid representation of data.

https://www.google.com/books/edition/6th_Grade_Math_Workbook...

You can't have a fraction of a person. The probability of having .65 out of 100 people working for Amazon is zero, no matter which 100 people you select. 1 out of 153 can at least happen.

We should start using the birthday paradox number (BPN) to express these things. That is, the smallest group of people such that the probability that at least one of them will exhibit the criteria is greater than 50%.

In this case, the BPN for working at Amazon is 107 (assuming everyone in the group is a worker).

X in <CONSTANT> is just the inverse of <CONSTANT> in X. Each is appropriate at different times. 0.0004 is the same as 1 in 2500. I feel like 1 in 2500 is more intuitive, and that's generally the case for rare events, because it is oriented around answering the question "how rare is this?"

"1 in Y" is simpler than "X in 100". 100 introduces an irrelevant big number.

I think OP's intuition is probably wrong and that "1 in Y" is more effective than "X%".

That being said, it is tricky to move the adjustment between the numerator and denominator, and there are cases where this choice can be key -- "25 miles per gallon" is indeed a far worse metric to use than "4 gallons per 100 miles".

It isn't if you know the capacity of your tank in gallons, and want to know how far you can drive on average before refilling it.

Or if you know the price of gasoline, and want to know how far you can drive for some amount of money.

In fact I'm struggling to come up with practical circumstances where gallons per 100 miles is what I'd want to know, could you explain why that seems better to you?

In Portugal (and I guess several other countries) fuel economy is defined as "how many liters per 100 km?". In Brazil it's "how many km per liter?".

> Equal increases in MPG are not equal in gas savings.

http://www.mpgillusion.com/p/what-is-mpg-illusion.html

Fuel economy is typically printed the same place range already is computed =)

mpg is used to indicate fuel economy, comparing among cars. People might think -- do think -- that the difference between a 15mpg car and a 25mpg car is similar to the difference between a 25mpg car and a 35mpg car. But the difference is nowhere close in amount of gas saved per year of similar driving between the two. The former is a great boon to the environment and the pocketbook, but the latter is much more modest.

I don't think I would see anything wrong with gallons per 100 miles if I was used to it. Especially if it was "gallons per megamile" or whatever.

You see (at least in the UK) dishwashers say they only use x litres of water per wash or even things like "this only costs 10p an hour running costs".

It feels like one less step to get to "how much would this car cost me for my 250 miles a week" - which seems more common than "I can afford exactly 2 gallons of petrol a week, how far can I get with this car".

Maybe I'd feel differently if we bought fuel in the same units we measured its consumption in!

I don't see anything wrong in measuring gallons per mile and measuring in yards and other non-metric systems when it's something local. Maybe it's convinient if you live somewhere where everybody accustomed to that.

It's when I see articles about space exploration with miles and pounds - it feels wrong.

Why is "1 in X" so much worse than "X in 100"?

Every time X goes up 1 in the first example, the amount that's actually changed is different. In the second, it's the same.

I've eaten 1/5 of the pizza. Now 1/4. Now 1/3. Slices are all different sizes.

I've eaten 20% of the pizza. Now 40%. Now 60%. Slices are the same.

It's not. They just need something to complain about.

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