The owner of 18 Sandwich King restaurants located in eastern Pennsylvania has asked you to help analyze the results of an experiment they have just completed. Last year, they met with consultants who suggested two ideas to help increase store profits:
Decrease staffing (too many employees were idle during non-rush hours)
Add in-store specials: either monthly (a “sandwich-of-the-month”) or daily (the same seven items rotating daily)
Each of the 18 stores were randomly assigned to one of six combinations of treatments:
No change in staffing, no specials
No change in staffing, daily specials
No change in staffing, monthly specials
Decreased staffing, no specials
Decreased staffing, daily specials
Decreased staffing, monthly specials
Your task: determine whether the staffing changes and/or specials had an effect on profit, and recommend what option(s) Sandwich King should implement going forward.
Summarize the data numerically and graphically. From the numerical and graphical summaries, what combination(s) of treatments appear to be most effective?
Perform two-way ANOVA to determine:
Whether any of the treatments had different effects from one another on store profits (Step 1, testing for any overall effect)
Whether the effect of specials differed depending on staffing changes (Step 2, testing for interaction)
If appropriate, which of the treatments (specials, staffing) had an effect on store profits (Step 3, testing separate effects)
Use Bonferroni post-hoc tests (if appropriate) to determine which treatments can be demonstrated to increase profits.
Make recommendations for which changes Sandwich King should make for all stores based on your analysis.
Write a case report summarizing your findings and submit it below.
