An insecticide company exposes 10,000 cockroaches to its newest product, and exposes another 10,000 to their previous formula. The researchers use videotape to count how many cockroaches are still alive, and how many appear to be in distress, at 10 second intervals. When the test is completed, the researchers determine the mean elapsed time before a cockroach was killed by each product.

Question

An insecticide company exposes 10,000 cockroaches to its newest product, and exposes another 10,000 to their previous formula.  The researchers use videotape to count how many cockroaches are still alive, and how many appear to be in distress, at 10 second intervals.  When the test is completed, the researchers determine the mean elapsed time before a cockroach was killed by each product. 
I. What is the population?
II. What is the sample?
III. Is the study observational or experimental?  Justify your answer.
IV. What are the independent and dependent variables?
V. For each of those variables, what level of measurement was used to obtain data from these variables?
VI. Classify those variables as either attribute or numerical.