1. An experiment was conducted to examine the yield of six different types of alfalfa. They were planted in four different locations, so we will consider the field as a second factor because different soil and moisture types can also have an effect on yield. The interaction plot below was obtained.
This plot indicates
A. an effect for alfalfa type only.
B. an effect for field only.
C. interactions are present.
2. Ninety-one students participated in a study in which some were randomly assigned to run a quarter mile and others were not. Their pulse rates were measured before running, and immediately after the run, even for those who didn't run. We are further interested in whether any pulse rate increase is similar for both females and males. The response variable is the difference in the pulse rates. In the graph below females are coded as 0 and males as 1. Runners were coded as 1.
This graph shows
A. running increases the pulse rate.
B. running increases the pulse rate, and the amount of increase is higher for females.
C. there was no running effect.