a. Determine equations for P=f(Q), MR=f(Q), ATC=f(Q, Q²), AVC=f(Q, Q²), MC=f(Q, Q²)

I need a quadratic equation for ATC, AVC and MC. When TC is put on scatter plot it is more suited for quadratic equation, but I do not know how to get there with this data. thank you.

Q	P	TC
0	$90	$2,000
10	$88	$2,770
20	$86	$3,320
30	$84	$3,710
40	$82	$4,000
50	$80	$4,250
60	$78	$4,520
70	$76	$4,870
80	$74	$5,360
90	$72	$6,050
100	$70	$7,000