[EMAIL PROTECTED] writes:
>My wife wants to adjust marks for a course she is marking. Does someone
>have
>a formula or something for using a bell curve to move them up or down?
>
>I have done this sort of thing about 15 years ago, but I can't remember
>any
>of it!
>
Use a calculator to find the average and the standard deviation of the
grades that she has. Then have her decide what grade she wants to be the
average of her adjusted class grades. She also needs to decide what
standard deviation she wants for her new grades. (I often use 80 as the
new average and 7 as the standard deviation.) Now, here is how to figure
the new grades:
new grade =[(old grade - old average)/old standard deviation]* new
standard deviation + new average.
For my scale, indicated above, the formula becomes
y = (x - avg)* 7 + 80
Hope this helps.
RGD
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Robert G. Davies
Woodberry Forest School
Woodberry Forest, VA 22989
(540) 672-3900
