Question

prelab practice problem: answer the following questions to practice using variables. you are interested in testing the following hypothesis: \students who drink coffee before an exam will score higher on the exam than students who dont drink coffee.\ a. for this experiment, identify the following: independent variable: __________ dependent variable: ________ two controlled variables: ________ control group: ________ experimental group: ________ b. the independent variable should be plotted on the __ axis and the dependent variable should be plotted on the ____ axis. c. what kind of graph (line or bar graph) would be more appropriate in graphing the data? why?

Explanation:

• a. The independent variable is what is manipulated - here, coffee - drinking status before an exam. The dependent variable is the result that is measured - exam scores. Controlled variables could be factors like amount of study time, type of exam, etc. The control group doesn't drink coffee and the experimental group does.
• b. By convention, the independent variable is plotted on the x - axis and the dependent on the y - axis.
• c. A bar graph is more appropriate as the independent variable (coffee - drinking or not) is categorical.

Answer:

a.
Independent variable: Whether a student drinks coffee before an exam
Dependent variable: Exam scores
Two controlled variables: Amount of study time, type of exam (answers may vary)
Control group: Students who don't drink coffee before an exam
Experimental group: Students who drink coffee before an exam
b. x; y
c. Bar graph. Because the independent variable (coffee - drinking status) is categorical.