Big Ideas Math Integrated I, 2016
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Big Ideas Math Integrated I, 2016 View details
5. Analyzing Lines of Fit
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Exercise 16 Page 197

Which variable do we use for the correlation coefficient?

The data have a strong negative correlation.

Practice makes perfect

Let's consider the graphing calculator display. We will use it to find and correct the error with the given interpretation.

Illustration of the LinReg(ax+b) window on the calculator

We can learn about the correlation and how well our line of fit represents the data by interpreting the correlation coefficient, r. r= -.9994724136 When | r| is close to 1, it means that there is a strong correlation and when r is close to 0, it means that there is a weak correlation. Let's investigate our correlation coefficient. | r|=| -.9994724136|=0.9994724136 This value of | r| is close to 1 which indicates a strong correlation. A positive value for r indicates a positive correlation and a negative value indicates a negative correlation. In this case, we have a negative correlation. We can now correct the error.