Many retailers, like grocery stores, practice a form of geographic segmentation, where they try to locate stores in areas with a specific mix of characteristics thought to be conducive to generating sales (e.g, neighborhood income, neighborhood education, traffic patterns, proximity to other kinds of stores, etc.) An upscale grocery store chain hired an economist to figure out which location-related factors best predict sales success. _____ is the approach to research that is best suited to answer this kind of marketing research question.