document.write( "Question 325577: the arithmetic mean of five numbers is 60. if the arithmetic mean of the first four numbers is 70, what is the fifth number? \n" ); document.write( "
Algebra.Com's Answer #233105 by mananth(16946)\"\" \"About 
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arithmetic mean of five numbers = 60
\n" ); document.write( "so the sum of the numbers = 60*5 =300
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\n" ); document.write( "first four numbers mean = 70
\n" ); document.write( "sum of these 4 numbers = 280.\r
\n" ); document.write( "\n" ); document.write( "so the 5th number is 300-280=20
\n" ); document.write( "the fifth number is 20
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