Casio fx-CG10 Advanced Operation Manual page 30

Sample Solution—Empowerment of Bangladesh Women (continued)
The correlation coefficient, r, is approximately 0.70. This suggests the data do
have a relatively strong linear trend. Let's try other types of regression too.
c. Now, try a quadratic regression.
quadratic equation?
To perform a quadratic regression:
From the scatterplot, press
x in a quadratic equation is of degree 2, and for this reason, we press x
to perform a quadratic regression.
Press
the scatterplot.
2
The r values are approximately 0.49 and 0.93 for the linear and quadratic
regressions, respectively. These values and an inspection of the scatterplots
suggest the quadratic function most accurately models the Women
Empowerment Index data as a function of the age of the women.
Fostering Advanced Algebraic Thinking with Casio Technology
(DRAW) to draw the regression equation on the same axes as
Which is the best fit—the linear or the
(CALC), then press
2
(x ). The variable
2