Description
Barney Fife works for the Mayberry Sheriff’s department. Currently, Barney is working on a patrol unit, but he is considering an assignment change. He could move from the patrol unit to either the court unit or working in the jail. Like the good ole boy he is, Barney wants to make sure that he is making enough money to support him and Thelma Lou and any pending children. To make his decision, Barney has collected the salary data for 30 officers, ten work in patrol, ten work in the court, and the last 10 work in the jail. Barney expects that working in one of these other units will more quickly allow him to be promoted and to increase his salary. Comparing all three assignments, Barney wants to know if there is a difference in salary between these assignments and if this difference is statistically significant. Using your skills from the most recent lecture, you offer to help Barney figure out which unit he should work in for the greatest salary potential.
Using the attached Police Data and SPSS calculate the following:
The patrol unit is coded as “1”, the court unit is coded as “2”, and the jail is coded as a “3”.
1. What are the mean salaries for those who work on patrol, in the courts, or in the jail?
2. State a Null Hypothesis and Alternative Hypothesis for Barney.
3. Conduct an ANOVA and interpret the Levene’s Test, can equal variances be assumed? How do you know?
4. If the Levene’s Test cannot be assumed, what test(s) can you use to check for significance within the ANOVA.
5. Conducting a Post Hoc test, perform hypothesis testing in two ways: the p-value approach and the confidence interval approach for each of the options. Is the null hypothesis you stated rejected? Demonstrate how you know for each test.
6. Provide a screenshot of the Means Plot
7. Based on your ANOVA results what would you suggest Barney do?