1. An experiment was conducted to determine the effects of three different pesticides (P1,P2,P3) on the yield of three different varieties of citrus tree (V1,V2,V3). Six trees of each variety were randomly selected from the orchard, and the three pesticides were than randomly assigned to the trees; two trees for each pesticide. Yields of fruit, in bushels per tree, were obtained after the test period.

Which of the following is true?

A. By studying pesticide and variety together, we can investigate the interaction between these factors.
B. It is generally less efficient to study two factors simultaneously, since the observations need to be divided up between the two factors.
C. Both choices are correct.

2. In many sports, there is a debate over the use of high-tech equipment to improve performance. A recent study in golf centered on both the use of high-tech equipment and whose performance would actually be improved. In the study, 60 golfers were selected at the beginning of the season: twenty at the beginner's level, twenty at the intermediate level, and twenty who were considered advanced golfers. Each level of golfer was randomly divided into two groups of 10 each. One group was given a titanium driver, and the other group was given weekly golf lessons from a pro. At the beginning of the season, the number of yards that each subject could drive the ball was computed, and at the end of the season this was done again. The variable recorded for each subject was the number of additional yards (possibly negative) that the subject could drive the ball by the end of the season. In the two-way ANOVA the DFM are

A. 1.
B. 2.
C. 5.