The mango is considered the "king of fruits" in many parts of the world. Mangoes are generally harvested at the mature green stage and ripen up during the marketing process of transport, storage, and so on. During this process, about 30% of the fruit is wasted. Because of this, the impact of harvest stage and storage conditions on the postharvest quality are of interest. In this experiment, the fruit was harvested at 80, 95, or 110 days after the fruit setting (the transition from flower to fruit) and then stored at temperatures of 20, 30, or 40 degrees centigrade. For each harvest time and storage temperature, a random sample of mangoes was selected, and the time to ripening was measured.

(a)What are the factors, the treatments, and the response variables? Use a diagram like Figure 9.2 to display the factors and treatments.

(b)For simplicity, the experimenter thought about selecting nine mango trees and randomly assigning one tree to each of the nine treatments. All the mangoes on a tree would then receive the same treatment. Do you think this would be a good way to assign the mangoes to the treatments?