Ameteorologist keeps hourly temperature records over the course of several years in order to look for long-term variations. this is an example of what kind of statistical study?

Observational study

Step-by-step explanation:

There are 3 types of statistical study:

1) Experimental: Under this, any experiment is done on a certain group of population.

2) Observational: Under this study, the events are observed regularly and the record is made.

3) Survey : Under this study, a survey is conducted with a a group of population and the record is made.

According to question, A meteorologist keeps hourly temperature records over the course of several years in order to look for long-term variations, this is an example of observational study.