Tom K. answered 09/14/20
Knowledgeable and Friendly Math and Statistics Tutor
Let me build on Mikd's last equation.
0.25^n <= .01
Take logs of both sides.
n ln(.25) <= ln(.01)
We can rewrite this as
n ln(4) >= ln(100)
n >= ln(100)/ln(4) = 2 ln(10)/2 ln(2) = ln(10))/ln(2)
Note that if you used log where log means log10, you could write this as
n >= 2/2 log(2) = 1/log(2)