As average income of a neighborhood increased, violent crime rate decreased. this information is an example of which kind of social research?

What are objects called that have value in and of themselves as well as value as a means of exchange? custom commodity money currency simple money

Martha participates in a research study in order to receive extra credit for her psychology class. when she arrives in the research office she is given a can of what looks and tastes like beer, but which actually contains no alcohol. in the adjoining room martha's classmate karen is also participating in the study. karen receives a can of alcoholic beer. if the experiment was designed to test the effects of alcohol on concentration, then who is exposed to the independent variable?

An refers to a specific factor that has a range of possible values