3. 11088 is $110\%$ of the containers in December compared to November. This means that in November, $11088: 1.10=10080$ containers were manufactured, which is $105\%$ compared to October. This means that in October, $10080: 1.05=9600$ containers were manufactured, which is $120\%$ compared to September. Therefore, in September, $9600: 1.20=8000$ containers were manufactured.
Answer: in September 8000, in October 9600, in November 10080 containers.