document.write( "Question 956464: How long does it take $775 to double if it invested at 5% interest compounded semiannually ? \n" ); document.write( "

Algebra.Com's Answer #584324 by josmiceli(19441) $\"\"$ $\"About$

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$\"+A+=+P%2A%28+1+%2B+r%2Fn+%29%5E%28n%2At%29+\"$
\n" ); document.write( " $\"+n+=+2+\"$
\n" ); document.write( " $\"+r+=+.05+\"$
\n" ); document.write( " $\"+P+=+775+\"$
\n" ); document.write( " $\"+A+=+2%2A775+\"$
\n" ); document.write( "----------------
\n" ); document.write( " $\"+1550+=+775%2A%28++1+%2B+.05%2F2+%29%5E%28+2t+%29+\"$
\n" ); document.write( " $\"+2+=+%28+1+%2B+.025+%29%5E%28+2t+%29+\"$
\n" ); document.write( " $\"+1.025%5E%282t%29+=+2+\"$
\n" ); document.write( "Take the log of both sides
\n" ); document.write( " $\"+2t%2Alog%28+1.025+%29+=+log%282%29+\"$
\n" ); document.write( " $\"+2t%2A.010724+=+.30103+\"$
\n" ); document.write( " $\"+t+=+.30103+%2F+.021448+\"$
\n" ); document.write( " $\"+t+=+14.0353+\"$
\n" ); document.write( "--------------
\n" ); document.write( "In 14 yrs, $775 will double
\n" ); document.write( " $\"+2+=+%28+1+%2B+.025+%29%5E%28+2t+%29+\"$
\n" ); document.write( " $\"+2+=+1.025%5E%28+2t+%29+\"$
\n" ); document.write( " $\"+2+=+1.025%5E%28+2%2A14.0353+%29+\"$
\n" ); document.write( " $\"+2+=+1.025%5E28.0706+\"$
\n" ); document.write( " $\"+2+=+1.99998+\"$
\n" ); document.write( "close enough
\n" ); document.write( " \n" ); document.write( "

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