Question: The manager of an SAT review program wonders whether the ethnic background of a student and the program's instructor affect the student's performance on the SAT. Four ethnicities and three instructors are examined. Ten student scores for each combination are sampled. A portion of the data is shown in the following table; the full data set can be found on the text website, labeled ANOVA-SAT.
In a report, use the sample information and α = 0.05 to:
1. Determine if there is any interaction between instructor and ethnicity.
2. Establish whether average SAT scores differ by instructor.
3. Establish whether average SAT scores differ by ethnicity.