Question: A soil scientist is considering the effect of soil pH level on the breakdown of a pesticide residue. Two pH levels are considered in the study. Because pesticide residue breakdown is affected by soil temperature, four different temperatures are included in the study.
(a) Draw the interaction plot by hand with pH being the trace factor.
(b) Is there interaction between factors pH and temperature? Use the interaction plot to justify your answer.
(c) Compute the main pH effects and the main temperature effects.
(d) Compute the interaction effects.