document.write( "Question 883807: If i have a 67% in math what do i need to get on the eoct that is worth 20% of my grade to pass the class? \n" ); document.write( "
Algebra.Com's Answer #534056 by SmithWillSuffice(4)\"\" \"About 
You can put this solution on YOUR website!
This is a question about weighted averages. In this case the \"weights\" are the proportions of the fimnal grade which are approtioned to each separate exam paper. \r
\n" ); document.write( "\n" ); document.write( "Assuming they have no other exams to make up their grade, and assuming a \"pass\" means getting above 50% overall, then we can solve this puzzle using simple algebra and knowing how to compute averages. We will also assume if EOCT is worth 20% of the overall grade, then the Maths score must be worth 80%. So these will be the weights for the final computed average. Weights do not always have to sum to =1, but if they are probabilities or percentages then they do need to sum to unity (otherwise it would imply you were missing something).
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\n" ); document.write( "Let \"x+\" be the minimum grade in the EOCT exam they need. If we knew \"+x+\" then their overall average grade would be,
\n" ); document.write( "Overall = \"+%28+0.8%2A67+%2B++0.2%2Ax%29%2F%280.8%2B0.2%29.+\"\r
\n" ); document.write( "\n" ); document.write( "Remember, for weighted averages we divide the weighted sum by the sum of the weights, not the number of items averaged.\r
\n" ); document.write( "\n" ); document.write( "Then we are simply being asked to solve for \"+x+\",
\n" ); document.write( "\"+50+=+%280.8%2A67+%2B++0.2%2Ax+%29%2F%281%29+\"
\n" ); document.write( "thus \"+50+=+0.8%2A67+%2B++0.2%2A+x+\"
\n" ); document.write( "thus \"+50+=+%288%29%2F%2810%29+%2A+67+%2B++%282%29%2F%2810%29+%2A+x++\"
\n" ); document.write( "thus \"+50+=+536%2F10+%2B++%282%29%2F%2810%29+%2A+x++\"
\n" ); document.write( "thus \"+%282%29%2F%2810%29+%2A+x+=+50+-++%28536%29%2F%2810%29++\"
\n" ); document.write( "thus \"+%282%29%2F%2810%29+%2A+x+=+%28500+-+536%29%2F%2810%29++\"
\n" ); document.write( "thus \"++2%2Ax+=+500+-+536++\"
\n" ); document.write( "thus \"+2%2Ax+=+-36+\"
\n" ); document.write( "thus \"+x+=+-%2836%29%2F%282%29+\"
\n" ); document.write( "thus \"+x+=+-18.+\"
\n" ); document.write( "That's the answer, believe it or not!
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\n" ); document.write( "What does it mean? It means you can afford a negative score on the final exam. Since placing your name on the exam paper will win you a score of 0\% at least, this is all you need. You cannot fail provided you turn up to hand in the EOCT exam paper. :-)\r
\n" ); document.write( "\n" ); document.write( "Reflect: If you don't believe that st answer, just imagine you do only get 0% on the EOCT exam. Then what is your final grade? \r
\n" ); document.write( "\n" ); document.write( "Answer: It will be,
\n" ); document.write( "\"+%280.8+%2A+67+%2B+0+%2A+0.2+%29%2F%280.8%2B0.2%29+=+53.6+\"
\n" ); document.write( "which is a pass.
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