The possible imposition of a residential property tax has been a sensitive political issue in a large city that consists of five boroughs. Currently, property tax is based on an assessment system that dates back to 1950. This system has produced numerous inequities whereby newer homes tend to be assessed at higher values than older homes. A new system based on the market value of the house has been proposed. Opponents of the plan argue that residents of some boroughs would have to pay considerably more on the average, while residents of other boroughs would pay less. As part of a study examining this issue, several homes in each borough were assessed under both plans. The percentage increase (a decrease is represented by a negative increase) in each case was recorded.

a. Can we conclude that there are differences in the effect the new assessment system would have on the five boroughs?

b. If differences exist, which boroughs differ? Use Tukey’s multiple comparison method.

c. What are the required conditions for your conclusions to be valid?

d. Are the required conditions satisfied?