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Topic: Re: symmetry and skewness
Replies: 0

 Larry Peterson Posts: 14 Registered: 12/6/04
Re: symmetry and skewness
Posted: Jun 10, 1996 2:20 PM

It's interesting to view the discussion on curve fitting. I think it
is important for students to understand such "parent" functions as

The AP Course Description speaks of making "transformations to achieve
linearity; logarithmic and power transformations." This is an
appropriate reason for students to graph the data first to determine
its probable parent function. Then the students can transform the
data to make to output liner. For example, If the data appears to
be quadratic and the output is in LIST2 then LIST3 would be the
sqrt(LIST2). The plot then becomes linear and can use a linear
regression Sqrt(y) = a+bx. Then y = (a+bx)^2. This preserves the
true idea of linear regressions and allows students to see how
residuals are an important tool for analyzing the projected model.
It is really the same idea as using log-log paper or semi-log paper.

There are several good activities that provide hands on investigation
for these type problems. I plan to use them so student understand
the mathematics behind the transformations as well as the statistics.
Larry Peterson
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