3 ms·
Maybe I'm obtuse but I'm not sure I understand what you mean by the "right side". You definitely want to use a number that's slightly larger than 100 ln(2) ~= 6
by patrec 10y ago
Maybe I'm obtuse but I'm not sure I understand what you mean by the "right side". You definitely want to use a number that's slightly larger than 100 ln(2) ~= 69.3 to account for the linear factor, but is there some inherent reason to use 72 rather than say 70 or 74, other than that assuming that 8% is some useful midpoint for the type of growth rates you're likely to be interested in?
- AnimalMuppet 10y agoI believe the point was, don't use 68 or 64.
- kalid 10y agoI think that's what he meant; round up (not down) because the next correction term in the series is positive. 72 is better (mentally) than 70 or 74 because it has more divisors.
- cperciva 10y ago72 is better than 70 or 74 because it's divisible by more small factors. My point was that it's fortunate that 72 is slightly more than 100 log 2 rather than slightly less; for "how long will it take for money to triple" (100 log 3 = 109.86) taking the closest number with lots of divisors would lead you to take a "rule of 108" but since 108 is slightly less than 100 log 3 instead of slightly more, it will produce larger errors for the common range of interest rates.