user: Question: What is the average Worst score for Mario Lopez as the Best dancer and Tango as the Dance?
Columns: ['Dance', 'Best dancer', 'Best score', 'Worst dancer', 'Worst score']
Types: ['text', 'text', 'real', 'text', 'real']
Sample row: ['Cha-cha-cha', 'Emmitt Smith', 30.0, 'Tucker Carlson', 12.0]
SQL:

assistant: SELECT AVG("Worst score") FROM "Table" WHERE "Best dancer" = 'Mario Lopez' AND "Dance" = 'Tango';