user: ### NOW ANSWER:
Question: What is the best time for Marcus Marshall?
Columns: ['Name', 'Team', 'Qual 1', 'Qual 2', 'Best']
Types: ['text', 'text', 'text', 'text', 'real']
Sample row: ['Paul Tracy', 'Forsythe Racing', '58.440', '57.419', 57.419]
SQL:

assistant: SELECT AVG("Best") FROM "Table" WHERE "Name" = 'Marcus Marshall';