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```
Date: 11/16/95 at 18:32:41
From: Fortino Martinez

If Johnny has a 82% average for the 1st 9wks and a 75% average for the
2nd 9wks, what grade would he have to get on the final to recieve 80%
semester grade in this class.  The grades are weighted as follows: each
9wks 40 % and the semester test 20%.

K Riggins CCHS
```

```
Date: 11/19/95 at 15:4:26
From: Doctor Ethan

Okay, good question.

Here is how it works.

.4 +.4 + .2 = 1

So what we are going to do is to set up an equation involving the
percentages of the present grades and how they add up.  It looks like
this:

.4(82) + .4(75) + .2 (XX) = 80

So to solve for XX  we simplify to

32.8 + 30 + .2(XX) = 80

SO.....

.2(XX) = 80 - 32.8 - 30

So .2(XX) = 17.2

Now divide both sides by .2

and XX = 86.

Hope that helps.

-Doctor Ethan,  The Geometry Forum

```
Associated Topics:
Middle School Algebra

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