การเชื่อมต่อหลายออเปอเรชัน

# Select the 'birth_date' from each dictionary in the bag
birth_date_bag = filtered_bag.____

# Extract the year as an integer from the birth_date strings
birth_year_bag = birth_date_bag.____(lambda x: ____)

# Calculate the min, max and mean birth years
min_year = ____
max_year = ____
mean_year = ____

# Compute the results efficiently and print them
print(____(____))