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Chapter 5: Bivariate Data
215
Example 5-7:
For the data in
Example 5-6
, what is the predicted number
of soft-drinks sold for a temperature of 85
0
F?
Solution:
Observe that the value of 85
0
F lies within the range of the
independent variable values. Recall that the daily high temperature was
assumed to be the independent variable.
Thus, the predicted number of soft-drinks sold is
̂
- 43.798 + 1.082
85 = 48.172
49.(always round up)
That is, based on the model, when the temperature is 85
0
F the predicted
number of soft drinks which will be sold from that vending machine is
approximately 49.
Once the regression model has been established then one may want to know
how well the model is fitting the data.
A widely used measure of fit for a regression model is the coefficient of
determination.
Section Review
5-7 The Coefficient of Determination
The
coefficient of determination
is a measure that allows us to determine
how certain one can be in making predictions with the line of best fit.
e-Self Review