ABC Company had an annual sales of 7m in 2020 and its year-end total assets were 3.5 m. In 2020, current liabilities were 2.75 m consisting of 750,000 in notes payable, 1.2 m in accounts payable, and 800,000 in accruals. For 2021, the company estimates that net profit margin will be 8%, and the payout ratio 70%. If assets and spontaneous liabilities increase in the same proportion as that of sales, how large a sales increase can the company achieve without having to raise funds externally? Show your working.