Compare the grades on a final math test of 25 students who use calculators and 25 students who do not use calculators. The students decide which group they are in.

A. ExperimentB. Observational Study

This is an Observational Study

Step-by-step explanation:

The students is deciding which group they will be in. According to this information we can say that this is a observational study. Investigator doesn't control the groups, each student decides their own choice. If investigator decided the groups then this experiment would be Experimental study.