<image>In a workshop of 120 workers, a random sample of 30 workers was taken to understand the number of parts processed daily by these workers. The survey results were organized, and an incomplete bar chart was drawn (as shown in the image). Based on the information in the graph, answer the following questions:

(1) Among the surveyed workers, the number of workers who process 9 parts per day is ______;
(2) Among the surveyed workers, the number of workers who process 12 parts per day is ______, the number of workers who process ______ parts per day is the highest, and the percentage of workers who process 15 parts per day among the surveyed workers is ______%;
(3) Based on the results of this survey, estimate the workshop's average number of parts processed per worker daily and the total number of parts processed daily in the workshop.

