Answer:
Randomized
Explanation:
Observational Studies and Randomized Trials are two ideal ways of determining the outcome of certain tests.
In the Observational course the study is conducted in a true to life scenario and the result of what happens is recorded. Meanwhile, in the Randomized Trial there purposefully placed conditions that are ideal and these are evaluated after specific interventions.
Since the pool manager did not let different pools grow algae at will before putting in the chemical this study would not be considered observational. Instead he set up three different pools of the same size with the similar amount of contaminants and then tested the algaecide. This classifies this as a Randomized Trial.
They are not in the cartoon above because they wouldn't fit. i think that may be the correct answer.
Answer:
Love and Compassion... :)
