A researcher wants to conduct an experiment to determine if eating a cookie before class each day improves students' grades. He uses two psychology classes for the experiment, providing daily cookies to one and nothing to the other. At the end of the semester, the researcher compares the final grades of students in the two classes. What is the independent variable for this experiment

Where did the constitutional convention take place

On a supply and demand graph, equilibrium is the point where the two curves meet. the supply curve begins. the supply curve ends. the demand curve ends.

Dr. robbins wants to know if there are different opinions regarding the value of public school education between native americans who have at least one relative who attended indian boarding school and native americans who have no family experience with indian boarding school. dr. robbins contacts 35 native american participants in each group. he wants each group to include younger as well as older adults, and a mix of male and female participants. he asks each person to complete a survey about their attitudes toward public education. the design of this study is: