Type- strengthen
Core- low percentage of residents with humanities degrees is the main reason why Metro City has higher income per capita than any other city of comparable size in our nation

Per capita income in a city= (weight of non-humanities graduate pool* average income of non-humanities graduate pool + weight of humanities graduate pool*average income of humanities graduate pool + weight of non-graduate pool* average income of non-graduate pool)/(sum of weights of the three groups)

A. Metro City residents with humanities degrees have higher income per capita than do people with humanities degrees in any other city of comparable size in the nation.- incorrect, this weakens our claim

B. The percentage of residents with university degrees is lower in Metro City than in any other city of comparable size in the nation.- incorrect, this does not strengthen
Lowest % of university graduates --> highest % of non-graduates--> weight of non-graduate pool is higher
Also, for metro city to have highest per-capita income, its non-humanities university graduates need to have a higher income per capita than do people with non-humanities degree in other city of comparable size

C. Nationwide, university graduates without humanities degrees typically earn more than do individuals without university degrees.- incorrect, this can be inferred from the premises-" university graduates generally earn more than people who are not university graduates, but those with humanities degrees typically earn less than do graduates with degrees in other disciplines"

D. Metro City residents with degrees outside the humanities have per capita income no higher than the per capita income of such residents of other cities of comparable size in the nation.- Correct, if the per capita income of non-humanities degree holder in Metro city is higher than per capita of such residents of other cities, then Metro city need not have the lowest % of residents with non-humanities degree for it to have highest per-capita income among comparable cities

E. In Metro City, a lower proportion of university graduates have humanities degrees than in any other city of comparable size in the nation.- incorrect, the proportion of university graduates who have humanities is no that relevant since we are already told that Metro city has low percentage of residents with humanities degrees.


Answer D