Endangered dwarf shrubs. Rugel’s pawpaw (yellow squirrel banana) is an endangered species of a dwarf shrub.

Biologists conducted an experiment to determine the effects of fire on the shrub’s growth (Florida Scientist, Spring 1997). Twelve experimental plots of land were selected in a pasture where the shrub is abundant. Within each plot, three pawpaws were randomly selected and treated as follows: One shrub was subjected to fire, another to clipping, and the third left unmanipulated (a control).

After five months, the number of flowers produced by each of the 36 shrubs was determined. The objective of the study was to compare the mean number of flowers produced by pawpaws for the three treatments (fire, clipping, and control).

a. Identify the type of experimental design employed, including the treatments, response variable, and experimental units.

b. Illustrate the layout of the design, using a graphic similar to Figure 10.21.

c. The ANOVA of the data resulted in a test statistic of F = 5.42 for treatments with p@value = .009.

Interpret this result.

d. The three treatment means were compared by Tukey’s method at a = .05. Interpret the results, shown as follows:

Transcribed Image Text:

Mean number of flowers: Treatment: 1.17 Control 10.58 17.08 Clipping Burning