ELI5: Explain Like I'm 5

Logarithmic mean

Logarithmic mean is a super smart math concept that helps us find the middle number between two different numbers. It's like trying to find the average of these two numbers, but it's special because it takes into account how the numbers change over time, like with growth rates or with any other things that change over time.

Okay, let's say we have two different numbers, like 10 and 100. Now we want to find the middle number between these two. The logarithmic mean tells us that the middle number is actually between the two numbers, but it's not just the average of the two. Instead, we use a special formula that uses the logarithms of the two numbers.

Okay, stay with me here… A logarithm is kind of like a puzzle that helps us find the power we need to raise a number to in order to get another number. So, for example, the logarithm of 100 with base 10 is 2, because 10 raised to the power of 2 is equal to 100.

Now, we take the logarithm of both numbers and add them together, then divide that sum by 2. Finally, we take the exponential (which is basically the opposite of a logarithm) of that result, and we get the logarithmic mean!

So in our example, the logarithm of 10 with base 10 is 1, and the logarithm of 100 with base 10 is 2. We add those together and get 3, then divide by 2 to get 1.5. Finally, we take the exponential of 1.5, which is about 31.62. So the logarithmic mean of 10 and 100 is approximately 31.62.

See, it's not so scary! The logarithmic mean formula just helps us find a special number that's somewhere between two other numbers, and it takes into account how those numbers change over time.