Question: Given a recent out break of illness caused by F. co li bacteria, the mayor in a large city is concerned that some of his restaurant inspectors are not consistent with their evaluation s o f a restaurant's cleanliness. In order to investigate this possibility, the mayor has five restaurant inspectors grade (scale of 0 to 100) the cleanliness of three restaurants. The results are shown in the accompanying tab le and can also be found on the text website, labeled Restaurants.
a. Use Excel to generate the ANOVA table.
b. At the 5 % significance level, can you conclude that average grades differ by restaurant?
c. If average grades differ by restaurant, use Tukey's HSD test a t the 5% significance level to determine which averages differ.
d. At the 5 % significance level, can you conclude that the average grades differ by inspector? Does the mayor have cause for concern?