Chapter 4.2, Problem 51E

To determine

To identify: units or subjects of experimentation, explanatory variables, treatments and response variables

Explanation of Solution

The capacity of pines to grow in shades is checked by an experiment. In studies, it is suggested that pine seedlings be planted in maximum sun, reduced to 25% by sun, and reduced to 5% by light by natural conditions. Find the subjects and the variables. In the described procedure, treatments and response variables.

In this experiment, the following are asked for details:

Subject: The pine forest contained in Arizona's dry forest is deemed experimental because the research is based on the capacity of pine trees.

Factors: Since the procedure is conducted on the influence of light, the key factor in the experiment is light.

Treatments: The light is broken into three distinct proportions.

1) Full sun: full light illumination pine seedlings.

2) Light decreased to 25% of average: 25% lower than usual light intensity to pine seedlings.

3) Light decreased to 5% natural: 5 percent less light than normal light is available for pine seedlings.

Thus, three treatments are described as follows in the experiment:

Total sun, reduced to 25% natural light and reduced to 5% natural light conditions

Response Variable: The weight of the dry plant is determined from various treatment conditions. The weight of the plant in the experiment is also the response component.