Average Balance

Each day your bank closes its books and you earns a few pennies' interest on the 18 grand you have in your savings account (good for you!). In order to earn the free set of Avengers-themed steak knives at the end of the year, you have to maintain an AVERAGE BALANCE of at least $15,000. There are 20 business days in the month this month and as long as your average balance remains above that level, then bully for you - you get the knives.

Figuring average balance is pretty easy. Add up the closing balance for each day and divide by the number of days you are looking at (in this case the 20 business days in the month) and you get the average. We know it might take a minute to flash back to junior high math, but you'll figure it out...