user: Question: What is the average NGC number that has a Apparent magnitude greater than 14.2?
Columns: ['NGC number', 'Object type', 'Constellation', 'Right ascension ( J2000 )', 'Declination ( J2000 )', 'Apparent magnitude']
Types: ['real', 'text', 'text', 'text', 'text', 'real']
Sample row: [5904.0, 'Globular cluster', 'Serpens', '15h18m33.8s', '°04′58″', 7.3]
SQL:

assistant: SELECT AVG("NGC number") FROM "Table" WHERE "Apparent magnitude" > 14.2;