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 what kind of statistic study?

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.

Read more on -