Seattle Radiology Group plans to invest in a new CT scanner. The group estimates $1,500 net revenue per scan. Preliminary market assessments indicate that demand will be less than 5,000 scans per year. The group is considering a scanner (Scanner B) that would result in total fixed costs of $800,000 and would yield a profit of $450,000 per year at a volume of 5,000 scans. What is the estimated breakeven volume (in number of scans) for Scanner B