Chapter 9 Comparing More Than Two Groups
Suppose you are a greenhouse manager and you want to compare the effects of six different fertilizers on the growth of geraniums. You have 30 plants, and you randomly assigned five plants to each of the six fertilizer groups. You carefully controlled other factors: you used the same type of soil for all 30 plants, you made sure that they all received the same number of hours of light each day, and you applied the fertilizers on the same day and in the same amounts to all 30 plants. At the end of this designed experiment, you measured the height of each plant. Now, you want to compare the six fertilizer groups in terms of plant height. This chapter discusses the analysis of this type of situation. This ...