Question:

In 200? a study was published investigating the effectiveness of various homework methods in students' learning outcomes, i.e. assisting students to learn the course material. Students took a pretest on a topic they had not seen before. Then they lwere randomly assigned to one of three homework assistance groups. After completing the homework they took another simiiar test on the same topic. The improvements in the gradesr the differenoe between the posttest and the pretest, were recorded for each student. The homework assistance methods were: 1} check gures at various steps in the solution; 2} a full solution: and 3) no solution. ls'there evidence that some homework methods are more successful than others in assisting students to learn course material? The Minitab output is provided in the data le; do not do any unnecessary calculations. Which of the following is the correct denition of the parameter p. ? Select one: 0 a. Where p1 represents the mean improvement in grades if students were in one of the homework assistance groups, for this population model of students. 0 in. Where p1 represents the mean improvement in grades if students were in the Check homework assistance groups. tot this population model of students. 0 c. Where [.11 represents the mean improvement in grades if students were in the Check. Full and No assistance groups, for this population model of students. 0 d. Where p1 represents the mean improvement in grades if students were in the Check homework assistance groups. for the students who chose to participate. The next few questions are asking you to check the required assumptions and conditions. For the independence assumption, clearly explain in the context of the question whether or not the assumption is met. For the remaining assumptionsr ciearly refer to the appropriate plotts} and how those plots show that the oonditions are met [or not}. independence Assumption: Use the randomization condition. in the context of the problem, to check if both independence within the groups {are the individuals independent of one another} and among the groups (are the groups independent of one another].