15.7. Linear Correlation http://www.ck12.org
Solution:Visualize and sketch the “line of best fit” for each set of points.
Note that in part a, the regression line does not touch any point. Instead, it captures the general trend of the data.
In part c, the correlation is not high enough in any direction to produce a regression line. The calculator may give
a regression line for scatterplots that look like part c, but you need to be very skeptical that there is actually a
relationship between the two variables.
Example C
Use your calculator to perform a linear regression on the following data. Then, predict the height of someone who
has shoe size 9.
TABLE15.12:
Shoe Size Height (in)
11 70
8.5 70
10 72
8 65
7 64Solution:First enter the data.
Next perform the regression. Notice that the calculator can perform linear regression in two ways that are essentially
the same. To keep consistent with ˆy=a+bx, use linear regression. This is option 8 in the [STATS], [CALC] menu.