user: Question: What is the average height for Hewitt class, with prom less than 86, and a Peak of Gragareth?
Columns: ['Peak', 'Height (m)', 'Prom. (m)', 'Class', 'Parent']
Types: ['text', 'real', 'real', 'text', 'text']
Sample row: ['Whernside', 736.0, 408.0, 'Marilyn', 'Cross Fell']
SQL:

assistant: SELECT AVG("Height (m)") FROM "Table" WHERE "Class" = 'Hewitt' AND "Prom. (m)" < 86.0 AND "Peak" = 'Gragareth';