Corn per acre tons of fertilizer used (vertical axis) (horizontal axis) 110 6 150 10 180 14 170 18 140 22 60 26 The relationship is and (linear or nonlinear) (positive and/or negative] For an initial In of the by (Increase/decre) (causal var) (# of units) (effect var) (incr/decreases) (# of units) If nonlinear, the then more (effect var) (incr/decreases) (slowly, rapidly)