Rule of 72

Author

Eric W. Weisstein
April 14, 2004

This notebook downloaded from http://mathworld.wolfram.com/notebooks/Business/Ruleof72.nb.

For more information, see Eric's MathWorld entry http://mathworld.wolfram.com/Ruleof72.html.

©2005 Wolfram Research, Inc. except for portions noted otherwise

Plot

MakeBoxes[xlabel1,TraditionalForm]:=RowBox[{"r"," ",RowBox[{"(","%",")"}]}]
MakeBoxes[xlabel2,TraditionalForm]:=RowBox[{SubscriptBox["r","actual"],"-",RowBox[{SubscriptBox["r",RowBox[{"rule"," ","72"}]]," ",RowBox[{"(","%",")"}]}]}]
MakeBoxes[ylabel,TraditionalForm]:=RowBox[{"t"," ",RowBox[{"(","years",")"}]}]

Show[GraphicsArray[
Block[{$DisplayFunction=Identity},{
Plot[Log[2]/Log[1+r/100],{r,1,20},Frame->True,PlotStyle->Red,FrameLabel->TraditionalForm/@{xlabel1,ylabel}],
Plot[Log[2]/Log[1+r/100]-72/r,{r,1,20},
Frame->True,PlotStyle->Red,FrameLabel->TraditionalForm/@{xlabel2,ylabel}]
}
]
]
]

Plot[((Log[2])/(Log[1+r])),{r,0,3}]

Series[((Log[2])/(Log[1+r])),{r,0,3}]