Astudy aims to evaluate the percent of adults whose right cerebral hemisphere is larger than their left hemisphere. a group of individuals aged 20 and older representative of the american adult population is asked to come to a brain-imaging facility to have their brains scanned. each individual's scan is then analyzed to identify whether the right or left cerebral hemisphere is larger. (a) what type of study is this?

Observational study

Explanation:

An observational study is a type of study in which individuals are observed and certain measures are measured but there's no intend to affect the actual outcome. In other words, no treatment is given to the individuals and there's no intervention done by the researcher.

In this example, the study aims to evaluate the percent of adults whose right cerebral hemisphere is larger than the right hemisphere. 20 people come and have their brains scanned. Then, the scan is analyzed to identify which hemisphere is larger.

In this study, we can see how individual's brains were observed and some measures were taken but there was no treatment given to them (the researchers were only interested in knowing which hemisphere was bigger).

Thus, this is an example of observational study.

b) to encourage free trade