A confounding variable is an extraneous variable that is related to your independent variable and might affect your dependent variable. In an ideal study, there will be no confounding variables.
For example, student accounts have a limit of $100 limit per day, while non-business accounts usually are limited to $500 withdrawals a day. For business accounts, the bank offers $1000 withdrawals in one day. Chase also offers customers a withdrawal limit of $1000 every 24 hours.
Customers can decrease spending and withdrawal limits. Bank of America has a standard of $500 maximum daily for ATM withdrawals, but its ATMs can dispense up to 40 bills at once, so customers can set their withdrawal limit as high as $800 online.