Dwarf shrubs are popular with model home landscapers. Stetson University researchers 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 dwarf shrubs were randomly selected and treated as follows: one shrub was subjected to fire, another to clipping, and the third was left unmanipulated (a control). After 5 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 dwarf shrubs 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 9.20.
c. The ANOVA of the data resulted in a test statistic of F = 5.42 for treatments, with an associated p-value of p = .009. Interpret this result.
d. The three treatment means were compared using Tukey's method at α = .05. Interpret the results shown below.

Transcribed Image Text:

Mean number of flowers: 17 10.58 Treatment: 1708 Control Clipping Burning