The individual in this study on having a cellphone out is a student.
An observational study can be defined as a type of scientific study in which a researcher observes and measures the effect of a diagnostic test, risk factors, and specific treatments on individuals without intervening, manipulating or changing those who are or aren't exposed to it (controlled conditions).
In this scenario, 250 byu students volunteered to participate in the observational study that is focused on determining the effect of having a cellphone out on productivity.
In conclusion, the individual in this observational study on having a cellphone out is a student.
Read more on an observational study here: https://brainly.com/question/10504402