I wrote this for our high school algebra one students. Students will need technology (a graphing calculator with the "STAT" feature will be sufficient) to perform the 16 linear regressions. Students should be familiar with vocabulary such as correlation, relationship, causation, extrapolation, interpolation, linear, non-linear, prediction, correlation coefficient, though in all honesty, the circuit leads them through these ideas. There is no answer key included since the answers are part of th