Mathematically analyze your data (make a regression equation, make a prediction, etc.) on this topic/research question below.

Topic: Encryption of Bank Accounts, Password

Passcode policy varies depending on the bank. Some require 4-digit and others 6-digit. Some requires letter while others don't. But which is better?

Research Question: How do we determine the best password policy that a bank offers? What can be done to strengthen a password policy of a certain bank?

The research question that is an application of permutation. To answer that, you compute the total permutation of the password in a certain bank. For example, if bank A and bank B offer 4-digit password, and Bank A allows you to repeat the digit while Bank B do not. Then we have

Bank A: 10*10*10*10=10000; so you have 10000 permutations

Bank B: 10*9*8*7=5040; so you have 5040 permutations

Thus, Bank A offers a wider range of password. So Bank A has a better password policy.