Question

which best describes the purpose of a control sample?
○ to have more quantitative data to analyze at the end of the experiment
○ to have more qualitative data to analyze at the end of the experiment
○ to compare its results to those of a well-known scientist
○ to compare its results to those with the experimental sample

Explanation:

A control sample in an experiment is used as a reference. Its main purpose is to be compared with the experimental sample (the one with the variable being tested) to see the effect of the variable. The first two options are incorrect because control samples aren't about just getting more quantitative or qualitative data. The third option is wrong as control samples are compared to experimental samples, not a well - known scientist's results.

Answer:

D. to compare its results to those with the experimental sample (assuming the options are labeled A, B, C, D in order as presented)