Lines+Graphs,+Circles+Graphs,+Lines+of+Best+fit+and+Scatter+Plots

http://www.regentsprep.org/Regents/math/ALGEBRA/AD4/indexAD4.htm

http://teachers.henrico.k12.va.us/math/hcpsalgebra1/module10-4.html

http://mrsbuellscpalgebra1.wikispaces.com/Unit+9+-+Analyzing+Graphs+and+Statistics

http://ckeating.wikispaces.com/Central+Tendency