Investigators planted pine seedlings in the greenhouse in either full light or light decreased to 5% of normal by shade cloth to find out how well these pines grow in shade. At the end of study, they dried the young trees as well as weighed them.
I. What is the population?
II. What is the sample?
III. Is the study observational or experimental? Justify your answer.
IV. What are the variables?
V. For each of those variables, what level of measurement (nominal, ordinal, interval, or ratio) was employed to obtain data from these variables?