This is fascinating!

I did not realize that fractional reserve banking could be modeled as an infinite geometric series, but it makes sense.

One Question -- "Sum of Money Lent" when k (bank number) = 4...
Shouldn't that be 368,559,000 rather than 315,414,900?

I was following along with you, and got the same numbers up until that point.
Just wondering if I went wrong somewhere.

Thanks for this eye-opening article!