user: Question: what is the number of area where the county is Marsabit?
Columns: ['Code', 'County', 'Former Province', 'Area (km 2 )', 'Population Census 2009', 'Capital']
Types: ['real', 'text', 'text', 'text', 'real', 'text']
Sample row: [10.0, 'Marsabit', 'Eastern', '66,923.1', 291166.0, 'Marsabit']
SQL:

assistant: SELECT "Area (km 2 )" FROM "Table" WHERE "County" = 'Marsabit';