user: Question: What is the population of the area with a median family income of $71,278?
Columns: ['Borough or Census Area', 'Per capita income', 'Median household income', 'Median family income', 'Population', 'Number of households']
Types: ['text', 'text', 'text', 'text', 'real', 'real']
Sample row: ['Denali', '$42,245', '$72,500', '$81,500', 1826.0, 806.0]
SQL:

assistant: SELECT "Population" FROM "Table" WHERE "Median family income" = '$71,278';