Guide to Sullivan’s Chapter 4
Copyright © 2008–2013 by Stan Brown, Oak Road Systems
Now we turn to two-variable (bivariate) numeric data.
Correlation analysis answers the question
how close do the data points stick to a straight line?
and regression analysis answers the question
which line fits the data points best?
Historically the two were separate, but your calculator does them
Here’s the agenda for this chapter:
- scatter plot (a/k/a scattergram)
- correlation coefficient, r
- regression line and residuals
- coefficient of determination, R²
- predicted average, ŷ
- computed residual, y−ŷ
- inference using decision points
Correlation and Regression
Chapter 4 of the
If there’s time in class.
we’ll work through pages 205–206 problem 23 as a second
Of course you’re free to delve further into the textbook if you
want more explanation and illustrations. Please note, however, that
the second paragraph of page 186 is wrong.
The Shoe-Size Lab is due in two weeks and
will use material from Chapter 4 only. Start now with the data
collection at least.
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