A three-factor experiment is conducted to investigate the yields of different brands of rice grown in controlled greenhouse conditions. The response variable is the rice yield, and factor A is rice variety with a = 3 levels. Two levels of fertilizer are considered (factor B) together with two amounts of sunshine (factor C). There are n = 4 replicate observations per cell and the data set is given in DS 14.2.1.
(a) Construct the analysis of variance table and summarize what you learn from it.
(b) Is there any evidence that increasing the amount of fertilizer increases the expected yield?
(c) Is there any evidence that the effect of increasing the sunlight depends upon the amount of fertilizer employed?
(d) Is there any evidence that the effect of increasing the sunlight depends upon which variety of rice is used?