We have here the formula for Compound Interest:
Where:
• A is the accrued amount.
,• P is the Principal (the original amount of money, the starting amount of money).
,• r is the interest rate.
,• n is the number of times per year compounded.
,• t is the time in years.
When we have that n is equal to 12, we are talking here about that the amount of money is being compounded monthly (we have 12 months in a year, 12 periods, n = 12). <em>Therefore, we are dividing the rate, r, by the number of compoundings per year, n, and this is the rate per each new compounding period of time, r/n, and, in this case, n = 12 (monthly interest rate). </em>
Therefore, in few words, the fraction (0.04/12) is the monthly interest rate (option C).
[If we see the other options, we have:
• The daily interest rate would be given by 0.04/365.
,• How long the money has been in the account is time, t.
,• The starting balance in the account is the Principal, P. ]
