For the purpose of this study, ten qualities of a livable city were chosen, including a low crime rate, cleanliness, cultural attractions, and other amenities. For each city in the study, scores from 1 (lowest) to 10 (highest) were assigned for each of the ten qualities. The ten scores for each city were then summed, yielding a total livability sore for each city. We hope the resulting ratings will help you in choosing your next place of residence.
The passage above makes which of the following assumptions?