document.write( "Question 780578: The mean of three test grades is 74. What must the fourth test grade be to increase the mean to 78? \n" ); document.write( "
Algebra.Com's Answer #475625 by rfer(16322)\"\" \"About 
You can put this solution on YOUR website!
(74+74+74+x)/4=78
\n" ); document.write( "222+x=78*4
\n" ); document.write( "222+x=312
\n" ); document.write( "x=312-222
\n" ); document.write( "x=90
\n" ); document.write( "
\n" );