In: Statistics and Probability
A researcher investigates the factors that are associated with the salaries of professors who teach courses at a major university. The researcher gathers data about the subject area and the salary per course for a random sample of professors. Data are found in the file Academic Salaries by Subject Area.
Salary per course | Subject | Salary per course | Subject | Salary per course | Subject | Salary per course | Subject |
1700 | Humanities | 2500 | Social Sciences | 2700 | Engineering | 2500 | Managament |
1900 | Humanities | 2300 | Social Sciences | 2800 | Engineering | 2600 | Managament |
1800 | Humanities | 2600 | Social Sciences | 2900 | Engineering | 2300 | Managament |
2100 | Humanities | 2400 | Social Sciences | 3000 | Engineering | 2800 | Managament |
2500 | Humanities | 2700 | Social Sciences | 2800 | Engineering | 3300 | Managament |
2700 | Humanities | 2400 | Social Sciences | 2700 | Engineering | 3400 | Managament |
2900 | Humanities | 2600 | Social Sciences | 3700 | Engineering | 3300 | Managament |
2500 | Humanities | 2400 | Social Sciences | 3600 | Engineering | 3500 | Managament |
2600 | Humanities | 2500 | Social Sciences | 3700 | Engineering | 3600 | Managament |
2800 | Humanities | 3500 | Social Sciences | 3800 | Engineering | ||
2700 | Humanities | 3300 | Social Sciences | 3900 | Engineering | ||
2900 | Humanities | 3600 | Social Sciences | ||||
3400 | Social Sciences |
Answer:
d)Are the assumptions of an ANOVA reasonably satisfied? Explain in reference to the plots.
The assumptions of an ANOVA reasonably do not satisfy because of the bimodal from residuals histogram. Out assumption unimodal normal distribution on residuals.
From the above Tuke's test, the confidence intervals of Humanities VS Engineering and Humanities VS Management does not include the value zero. Hence, we can conclude that the salary per course between the Humanities & Engineering and Humanities & Management have a significant difference at the 0.05 significance level.