A poultry experiment was run to investigate the effect of diet and antibiotic on egg production. They evaluated 2 diets of interest, and 2 specific antibiotics of interest. The feed and antibiotic were combined and used to fill a single feeding tray in each barn. They chose 3 poultry farms at random and used 4 barns on each farm to accommodate the combinations of diet and antibiotic (assigned at random). Average egg production per chicken was recorded after 4 weeks. 

1. How many replications were there? 

2. What was the experimental design? (CRD, RCBD, or Latin Squares?) 

3. For farm, barn, diet and antibiotic, which are fix factors, which are random factors, and which are the experimental units? 

4. What are the null and alternative hypothesis being tested for the effect of the farms?