In terms of exponential growth and decay, you would start by putting it into the formula, "f(x)=a⋅b^x". You'll put 3 as a and since it's increasing double (or 100%) each month, you'll put b as 2 since you need to add one unit. For ^x, you'll add 12 since there are 12 months in a year. Your completed formula would come out as 3(2)^12 which would come out to 12288.
