What are the highest cost, lowest cost and average cost of procedures?
SELECT MAX(cost) ,  MIN(cost) ,  AVG(cost) FROM procedures
SELECT MAX(cost) ,  MIN(cost) ,  AVG(cost) FROM procedures
[{'MAX(cost)': 10000.0, 'MIN(cost)': 25.0, 'AVG(cost)': 4324.857142857143}]