Answer
The text part of the statistical study is shown in the step by step section.
We can identify that the daily dose of the compound is the independent variable
as this quantity was set and varied by the people performing the experiment.
The dependent variable would be the amount of the beneficial species which
increased in response to the independent variable.
Work Step by Step
According to a pilot study of
20 people conducted at the University of Minnesota,
daily doses of a compound called arabinogalactan over a
period of 6 months resulted in a significant increase in
the beneficial lactobacillus species of bacteria.