The grades.sav file is a sample SPSS data set. The data represent a teacher’s recording of student demographics and performance on quizzes and a final exam across three sections of the course. Each section consists of 35 students (N = 105). There are 21 variables in grades.sav.
This week’s assignment is on t-tests. You will analyze the following variables in the grades.sav data set:
SPSS Variable Definition
Gender female = 1; male = 2
GPA previous grade point average
Step 1: Write Section 1 of the DAA: The Data Analysis Plan
Name the variables used in this analysis and whether they are categorical or continuous.
State a research question, null hypothesis, and alternate hypothesis for the independent samples t-test.

Step 2: Write Section 2 of the DAA: Testing Assumptions
Test for one of the assumptions of t-tests – homogeneity of variance.
Create SPSS output showing the Levene’s Test for Equality Variances. Run the Levene’s test on the dependent variable test for the entire sample. Do not split the data up by gender before running the homogeneity test.
Paste the table in the DAA.
Interpret the Levene’s test.

Step 3: Write Section 3 of the DAA: Results and Interpretation
Paste the SPSS output of the t test. Below the output:
Report the means and standard deviations for each group.
State the results of the t-test using the “Assume equal variances” row.
Interpret the statistical results against the null hypothesis and state whether it is accepted or rejected.

Step 4: Write Section 4 of the DAA: Statistical Conclusions
Provide a brief summary of your analysis and the conclusions drawn about this t-test.
Analyze the limitations of the statistical test and/or possible alternative explanations for your results.

Step 5: Write Section 5 of the DAA: Application
Analyze how you might use the independent samples t-test in your field of study.
Name an independent variable and dependent variable that would work for such an analysis and why studying it may be important to the field or practice.