A company has achieved cost savings, which has increased its overall net profit. Net income from January through May 2020 is as follows:

Months	1	2	3	4	5
Net income (in units: 10,000 won)	4000	4400	5200	6400	8000

1) To predict future net income using net income for five months. Use the best least squares estimation to approximate the net gain with a quadratic polynomial. 2) Predict the net profit for December 2020.