Question

a pharmaceutical company will be testing a new \one - dosage fits all\ medication for treating depression. the pharmaceutical company has 100 willing test subjects that will undergo a 30 - day, double - blind experiment. the experiment uses the following diagram as a guide for administering the medication at various doses, from 5% to 125%.
what is the most obvious factor missing from this proposed experiment?
○ nothing is missing. basic variations have been accounted for.
○ blocking must be used.
○ a control group
○ a 100% dose
○ stratifying must be used.

Explanation:

In a scientific experiment, a control group (a group that receives no treatment or a standard treatment) is essential to compare the effects of the experimental treatments. Here, all groups are given different doses (experimental treatments), but there's no group with no medication or a placebo (control) to see if the medication has an effect relative to no treatment. Blocking is for accounting for confounding variables, stratifying is for sampling, and a 100% dose isn't necessary as the experiment tests from 5% to 125%. So the missing factor is a control group.

Answer:

C. A control group