As seen on the below map, 75 would be closer to 100 than 80 would much of the time.
That’s because interstates running vertically end in -5, while interstates running horizontally end in -0. So even though 80 and 100 would both be horizontal, they’d basically run parallel while 75 would intersect with 100 at some point, making them closer than 80 and 100.
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Of course you weren’t talking about interstates, but it was perfect to prove my point: you’re trying to be black-and-white when there is a lot of gray in this discussion. That gray refers to whatever is specifically being analyzed.
A perfect example:
Assume a baseball player had 500 at bats. Assume he hit .160, which means he had 80 hits. In order for him to increase his average to .200, he would have to hit 50% better over his next 500 at bats. Improving by 50% is a huge jump to reach. Even though .160 is 80% of 200, the player was nowhere close to hitting .200.
On the other hand, assume he only had 20 at bats and only had three hits. He would have an average of .150. Yet he would only be one hit away from having hit .200, so saying he was close to hitting .200 is logical and makes sense in that situation. Even though his average was only .150 (compared to the example above where his average was .160), the guy who went 3-20 is far closer to hitting .200 since he was only one hit away from reaching that level.
So in this case, which is closer to .200? .160 or .150? By far, the .150 is closer to .200 than the .160.
It goes back to what I have faulted you on before (and is yet another of my top strengths, as told to me by the Brown University grads who ran footballoutsiders.com): statistical analysis. You struggle with it, and the example above is proof of why it is so important.