Solution Found!
Homework assistance for accounting students. Refer to
Chapter 12, Problem 78E(choose chapter or problem)
Homework assistance for accounting students. Refer to theJournal of Accounting Education (Vol. 25, 2007) study of assisting accounting students with their homework, Exercise9.30 (p. 510). Recall that 175 accounting students took a pretest on a topic not covered in class and then each was given homework problem to solve on the same topic. The students were assigned to one of three homework assistance groups.Some students received the completed solution, some were given check figures at various steps of the solution, andsome received no help at all. After finishing the homework,the students were all given a posttest on the subject. Thedependent variable of interest was the knowledge gain(or test score improvement). These data are saved in the file.
a. Propose a model for the knowledge gain (y) as a function of the qualitative variable, homework assistance group.
b. In terms of the β’s in the model, give an expression for the difference between the mean knowledge gains of students in the “completed solution” and “no help” groups.
c. Fit the model to the data and give the least squares prediction equation.
d. Conduct the global F-test for model utility usingα = .05. Interpret the results, practically.
e. Show that the results, part d, agree with the conclusions reached in Exercise 9.30.
Questions & Answers
QUESTION:
Homework assistance for accounting students. Refer to theJournal of Accounting Education (Vol. 25, 2007) study of assisting accounting students with their homework, Exercise9.30 (p. 510). Recall that 175 accounting students took a pretest on a topic not covered in class and then each was given homework problem to solve on the same topic. The students were assigned to one of three homework assistance groups.Some students received the completed solution, some were given check figures at various steps of the solution, andsome received no help at all. After finishing the homework,the students were all given a posttest on the subject. Thedependent variable of interest was the knowledge gain(or test score improvement). These data are saved in the file.
a. Propose a model for the knowledge gain (y) as a function of the qualitative variable, homework assistance group.
b. In terms of the β’s in the model, give an expression for the difference between the mean knowledge gains of students in the “completed solution” and “no help” groups.
c. Fit the model to the data and give the least squares prediction equation.
d. Conduct the global F-test for model utility usingα = .05. Interpret the results, practically.
e. Show that the results, part d, agree with the conclusions reached in Exercise 9.30.
ANSWER:
Step 1 of 7
A model relating E( y) to one qualitative independent variable with k levels:
Always use a number of dummy variables that is one less than the number of levels of the
qualitative variable. Thus, for a qualitative variable with k levels use k -1 dummy
variables:
Where 
