Wed, 02 Jan 2008 15:22:49 -0600 from -Lost
<maventheextrawords@[EMAIL PROTECTED]
>:
> I'm starting a new degree and had to take a math placement test -- of
> course I bombed as usual. The minimum requirement was 41, I got a 21.
>
> Anyway, one problem that perplexed me slightly was:
>
> Mark took a French exam that consisted of 50 questions. He got an 80%
> on 15 true or false questions and a 60% on 35 multiple choice
> questions.
>
> I couldn't figure it out, but ended up guessing that it was 70.
Just for the record, you haven't told us what the actual *question*
was. I'm guessing that it was to know his overall grade on the
questions, but that is a guess.
One key to success on tests, particularly math tests, is to think
logically and precisely. You need to cultivate the habit of mind that
focuses on "what is this question asking me?" If you train yourself
to do that, you will find you performance improving.
> So is it just the average of the 2 scores? The number of problems
> doesn't matter?
Is that logical? If you're looking for average gas mileage of a fleet
of two Rolls-Royces and 98 Civics, does it make sense to find the
average for the Rolls-Royces and the average for the Civics, and then
average the two numbers. I hope you'll realize it's obvious that the
bigger sample will carry more weight.
But you don't have to worry about formulas. Just ask yourself what an
exam average is. It must be number of points earned divided by number
of points possible. How many points did Mark earn? He got 80% of 15
T/F correct: .80*15 = 12. He got 60% of 35 M/C correct: .0*35 = 21.
So he earned 12+21 = 33 points. How many were possible? 15+35 = 50.
What was his average? 33/50 = 66%.
Ths makes sense (and you should *always* ask whether your answer
makes sense). The average is between the two partial averages, but
it's closer to the one that represents the larger number of
questions.
--
Stan Brown, Oak Road Systems, Tompkins County, New York, USA
http://OakRoadSystems.com/
"If there's one thing I know, it's men. I ought to: it's
been my life work." -- Marie Dressler, in /Dinner at Eight/
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