WORKSHEET - Compound Interest.
Amount after 10 yrs at 5%:
Difference: 9988.38 - 7411.54 =
after 5 yearsA=
=
A = =
A =
y =
A=
( )
A = final amount after earning interest P = Principal or beginning amount n = # of times compounded per yr.r = rate of int. t = time in years
A = ?P=50000r = 3%=.03n = 12t = 5 yr.nt = 12(5)= 60
A = ?P = 10000r = 4.5% = .045n = 4 (times a yr)t = 15nt = 4(15)=60
If you know n and t, we recommend plugging in all the #s on the right & doingthe arithmetic.If you do not know both n and t, thengraph the equation on a graphing calcu-lator, then look up the answer on the TABLE.
A = over 58080.84P = 40000r = 5% = .05n = 12t = ?nt = 12t
Use arithmetic:
Put equation in graphing calculator: A=40000(1+.05/12)^(12t). Look on theTABLE for where A is more than 58080.84.The x column will be time in years.
A = ?P = 43000r = 6% = .06n = 1 time a yr.t = 3nt = 3
A = ?P = 4500r = 5% = .05n = 12 times/yr.t = 10nt = 12(10) = 120
A = ?P = 4500r = 8% = .08n = 12t = 10 nt = 120
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Amt after 10 yrs at 8%:
Graph:
Use arithmetic:
Use arithmetic:
Use arithmetic:
