Rural households have more purchasing power than do urban households at the…

Key inference: The passage indicates that at the same income level, rural households have more income available for non-food and non-shelter needs because some of the income urban and suburban households must spend on food and housing can be spent by rural households on other things.

• Rural households have lower food and housing costs than do either urban or suburban households: This inference is best supported because lower spending on food and shelter explains why rural households would have more disposable income at the same income level.

• The average rural household includes more people than does the average urban or suburban household: The passage gives no information about household size. Moreover, larger households would normally reduce per-household disposable income, so this does not support the passage.

• Suburban households generally have more purchasing power than do either rural or urban households: The passage does not compare suburban purchasing power to the others generally; it explains why rural households can have more purchasing power at the same income, so this claim is unsupported.

• The median income of urban and suburban households is generally higher than that of rural households: The passage compares purchasing power at the same income level and gives no information about median incomes, so this cannot be inferred.

Conclusion: The statement that rural households have lower food and housing costs is the best-supported inference because it directly explains how rural households could have more purchasing power when incomes are equal.