document.write( "Question 6356: A=$6000 P= $1000 interest is 12% compounded quarterly Find # of interest periods \n" ); document.write( "
Algebra.Com's Answer #3407 by AnlytcPhil(1810)\"\" \"About 
You can put this solution on YOUR website!
A=$6000 P= $1000 interest is 12% compounded quarterly
\n" ); document.write( "Find # of interest periods
\n" ); document.write( "`
\n" ); document.write( "The formula is
\n" ); document.write( "`
\n" ); document.write( "A = P(1+r/n)nt
\n" ); document.write( "`
\n" ); document.write( "Where
\n" ); document.write( "`
\n" ); document.write( "A = ending amount = 6000
\n" ); document.write( "P = beginning amount = 1000
\n" ); document.write( "r = annual rate expressed as a decimal = .12
\n" ); document.write( "n = number of interest periods per year = 4
\n" ); document.write( "` ` (since it's quarterly)
\n" ); document.write( "t = number of years (which we find first)
\n" ); document.write( "`
\n" ); document.write( "A = P(1+r/n)nt
\n" ); document.write( "`
\n" ); document.write( "Taking logs of both sides
\n" ); document.write( "`
\n" ); document.write( "logA = log[P(1+r/n)nt]
\n" ); document.write( "`
\n" ); document.write( "logA = logP + log(1+r/n)nt
\n" ); document.write( "`
\n" ); document.write( "logA = logP + nt[log(1+r/n)]
\n" ); document.write( "`
\n" ); document.write( "logP + nt[log(1+r/n)] = logA
\n" ); document.write( "`
\n" ); document.write( "nt[log(1+r/n)] = logA - logP
\n" ); document.write( "`
\n" ); document.write( "nt[log(1+r/n)] `` logA - logP
\n" ); document.write( "-------------- = -------------
\n" ); document.write( "`n[log(1+r/n)] ` n[log(1+r/n)]
\n" ); document.write( "`
\n" ); document.write( "nt[log(1+r/n)] `` logA - logP
\n" ); document.write( "-------------- = -------------
\n" ); document.write( "`n[log(1+r/n)] ` n[log(1+r/n)]
\n" ); document.write( "`
\n" ); document.write( "` ` ` ` ` ` ` ``` logA - logP
\n" ); document.write( "` ` ` ` ` ` `t = -------------
\n" ); document.write( "` ` ` ` ` ` ` `` n[log(1+r/n)]
\n" ); document.write( "`
\n" ); document.write( "` ` ` ` ` ` ` ``` log6000 - log1000
\n" ); document.write( "` ` ` ` ` ` `t = --------------------
\n" ); document.write( "` ` ` ` ` ` ` ` ` `4[log(1+.12/4)]
\n" ); document.write( "`
\n" ); document.write( "` ` ` ` ` ` ` ``` 3.77815125 - 3
\n" ); document.write( "` ` ` ` ` ` `t = --------------------
\n" ); document.write( "` ` ` ` ` ` ` ` ` `4[log(1.03)]
\n" ); document.write( "`
\n" ); document.write( "` ` ` ` ` ` ` `` ` .7781512504
\n" ); document.write( "` ` ` ` ` ` `t = ---------------
\n" ); document.write( "` ` ` ` ` ` ` ` ` `.0513488988
\n" ); document.write( "`
\n" ); document.write( "` ` ` ` ` ` ` `` ` .77815125
\n" ); document.write( "` ` ` ` ` ` `t = ---------------
\n" ); document.write( "` ` ` ` ` ` ` ` ` `.0513488988
\n" ); document.write( "`
\n" ); document.write( "` ` ` ` ` ` `t = 15.15419548 years
\n" ); document.write( "`
\n" ); document.write( "Multiply by 4 to get the number of interest periods
\n" ); document.write( "`
\n" ); document.write( "Answer = 60.61678192 which means that 60 interest periods will
\n" ); document.write( "yield slightly less that $6000, or $5891.60 and 61 interest period
\n" ); document.write( "will yield slightly more than $6000, or $6068.40.
\n" ); document.write( "`
\n" ); document.write( "Edwin J
\r
\n" ); document.write( "\n" ); document.write( " \r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "
\n" ); document.write( "
\n" );