Question

independent practice
for his statistics class, a research student decided to study how parents income affects childrens performance on standardized tests like the sat. he collects the information from a random sample of test takers to examine the relationship between parental income and sat score.
is this an experiment? if not, what kind of study is it?
it is not an experiment. it is a matched - pairs design study.
it is not an experiment. it is an observational study.
it is an experiment.
it is not an experiment. it is a block design study.

Explanation:

An experiment involves manipulating an independent variable to observe its effect on a dependent variable. Here, the student is only collecting data from a random sample (observing) without manipulating parental income. A matched - pairs design and block design are types of experimental designs. An observational study simply observes and measures variables without intervention.

Answer:

It is not an experiment. It is an observational study.