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.
Debit Card: For cash withdrawals at ATMs, the daily limit is $500 per card. For all other debit card uses (payment for purchases, including any cash back, and non-ATM cash advances at financial institutions), the aggregate daily limit is $2,500 per card. For 16 and 17 year olds, there is a $300 aggregate daily limit per card. The limit can increase at age 18 if the member reapplies.