document.write( "Question 486077: how do you find the missing number to get a certain average with 5 numbers. \n" ); document.write( "

Algebra.Com's Answer #332395 by ankor@dixie-net.com(22740) $\"\"$ $\"About$

You can put this solution on YOUR website!
how do you find the missing number to get a certain average with 5 numbers.
\n" ); document.write( ":
\n" ); document.write( "Let x = the missing grade
\n" ); document.write( "An example the 5 grades: 84, 88, 79, 92, x
\n" ); document.write( "The certain average is 85
\n" ); document.write( ":
\n" ); document.write( "The equation
\n" ); document.write( " $\"%2884%2B88%2B79%2B92%2Bx%29%2F5\"$ = 85
\n" ); document.write( "which is:
\n" ); document.write( " $\"%28343%2Bx%29%2F5\"$ = 85
\n" ); document.write( "multiply both sides by 5,
\n" ); document.write( "343 + x = 5*85
\n" ); document.write( "343 + x = 425
\n" ); document.write( "subtract 343 from both sides
\n" ); document.write( "x = 425 - 343
\n" ); document.write( "x = 82 would be the missing grade to obtain an 85 average
\n" ); document.write( " \n" ); document.write( "

\n" );