Orange trees: An agricultural scientist wants to determine how the type of fertilizer and the type of soil affect the yield of oranges in an orange grove. He has two types of fertilizer and three types of soil. For each of the six combinations of fertilizer and soil, the scientist plants four stands of trees and measures the yield of oranges (in tons per acre)

from each stand. The data are shown in the following table.

a. Can you reject the hypothesis of no interactions? Explain.

b. Can the main effect of fertilizer on the yield of oranges be interpreted? If so, interpret the main effect, using the α = 0.05 level of significance. If not, explain why not.

c. Can the main effect of soil on the yield of oranges be interpreted?
If so, interpret the main effect, using the α = 0.05 level of significance. If not, explain why not.

Transcribed Image Text:

Soil Type 1 Soil Type 2 Fertilizer A Fertilizer B 20 24 22 9 23 23 30 24 22 22 27 25 23 29 31 32 Soil Type 3 29 25 23 28 25 29 30 31