Question

underline the best answers.
3.1) an (analysis, experiment, investigation) is a test to try to find an answer to a question.
3.2) a (hypothesis, prediction, conclusion) is a possible explanation or guess for what might happen during an experiment.
3.3) a(n) (controlled variable, hypothesis, independent variable) is something that is changed in an experiment.
3.4) a(n) (controlled variable, hypothesis, independent variable) is something that stays the same in an experiment.

Explanation:

3.1) An experiment is a test to find an answer to a question. Analysis is examining data and investigation is a broader study.
3.2) A hypothesis is a possible explanation or guess for what might happen during an experiment. Prediction is more about foretelling and conclusion is the end - result.
3.3) An independent variable is what is changed in an experiment. A controlled variable is kept the same and hypothesis is an explanation.
3.4) A controlled variable stays the same in an experiment. An independent variable is changed and hypothesis is an explanation.

Answer:

3.1) experiment
3.2) hypothesis
3.3) independent variable
3.4) controlled variable