5.6.1 Scatter Plots and Equations of Lines

Remember our Stroop test? During the stroop test we used the tool called scatter plot A scatter plot is a collection of points Includes  axis labels  Points  Line of best fit

Correlation Positive Correlation: No Correlation: Negative Correlation:

Correlation Co-efficient (r) The correlation Co-efficient, r, is determined to describe the correlation types stronger positive correlations and r is near 1 stronger negative correlations and r is near -1 If there is no correlation r is near < r <.25 No Correlation -.85 < r < -1 Strong Negative.5 < r <.85 Weak Positive

Line of best fit Using two points Using a graphing utility TI-83

Choosing two points Choosing two points the “fit” the data best Use a ruler Same # of points above as below the ruler Do the same process as we did in 5.5 Does work but is unreliable method See appendix graph

TI-83 Calculator Using the TI 83 calculator, enter the data “STAT” button  edit L1 should be “x” axis, L2 should be “y” “WINDOW” button Set window “Y=“ button, Highlight “Plot1” GRAPH

Graphing Utility World/newgraph/regressionframes.html World/newgraph/regressionframes.html Use like a graphing calculator Easier maybe? Harder to find.

Look at page 242

Homework p odd, 8-10, 11, 13, 16, 21, 23, 29