An airline wants to select a computer software package for its reservation system. Four software packages (1, 2, 3, and 4) are commercially available. The airline will choose the package that bumps as few passengers as possible during a month. An experiment is set up in which each package is used to make reservations for 5 randomly selected weeks. (A total of 20 weeks was included in the experiment.) The number of passengers bumped each week is obtained, which gives rise to the following Excel output:
ANOVA
Source of Variation SS df MS F P-value F crit
Between Groups 212.4 3 8.304985 0.001474 3.238867
Within Groups 136.4 8.525
Total 348.8
a) What is the within groups degrees of freedom for this analysis? Explain how you obtain your answer.
b) What are the total degrees of freedom? Explain how you obtain your answer.
c) What are the among-group (between-group) mean squares? Explain how you obtain your answer.
d) At a significance level of 1%, what conclusion can you infer? Explain how you obtain your answer.