help with excel

Sheet1

X	Y		Slope
2	13
2.5	18.75		11.5
3	26		14.5
3.5	34.75		17.5
4	45		20.5
4.5	56.75		23.5
5	70		26.5
5.5	84.75		29.5
6	101		32.5
6.5	118.75		35.5
7	138		38.5
7.5	158.75		41.5
8	181		44.5
8.5	204.75		47.5
9	230		50.5
9.5	256.75		53.5
10	285		56.5
10.5	314.75		59.5
11	346		62.5
11.5	378.75		65.5
12	413		68.5
12.5	448.75		71.5
13	486		74.5
13.5	524.75		77.5												`
14	565		80.5
14.5	606.75		83.5
15	650		86.5
15.5	694.75		89.5
16	741		92.5
16.5	788.75		95.5
17	838		98.5
17.5	888.75		101.5
18	941		104.5
18.5	994.75		107.5
19	1050		110.5
19.5	1106.75		113.5
20	1165		116.5
20.5	1224.75		119.5
21	1286		122.5
21.5	1348.75		125.5
22	1413		128.5
22.5	1478.75		131.5
23	1546		134.5
23.5	1614.75		137.5
24	1685		140.5
24.5	1756.75		143.5
25	1830		146.5
25.5	1904.75		149.5
26	1981		152.5
26.5	2058.75		155.5
27	2138		158.5
27.5	2218.75		161.5
28	2301		164.5
28.5	2384.75		167.5
29	2470		170.5
29.5	2556.75		173.5
30	2645		176.5
30.5	2734.75		179.5
31	2826		182.5
31.5	2918.75		185.5
32	3013		188.5
32.5	3108.75		191.5
33	3206		194.5
33.5	3304.75		197.5
34	3405		200.5
34.5	3506.75		203.5
35	3610		206.5
35.5	3714.75		209.5
36	3821		212.5
36.5	3928.75		215.5
37	4038		218.5
37.5	4148.75		221.5
38	4261		224.5
38.5	4374.75		227.5
39	4490		230.5
39.5	4606.75		233.5
40	4725		236.5
40.5	4844.75		239.5
41	4966		242.5
41.5	5088.75		245.5
42	5213		248.5
42.5	5338.75		251.5
43	5466		254.5
43.5	5594.75		257.5
44	5725		260.5
44.5	5856.75		263.5
45	5990		266.5
45.5	6124.75		269.5
46	6261		272.5
46.5	6398.75		275.5
47	6538		278.5
47.5	6678.75		281.5
48	6821		284.5
48.5	6964.75		287.5
49	7110		290.5
49.5	7256.75		293.5
50	7405		296.5
50.5	7554.75		299.5
51	7706		302.5
51.5	7858.75		305.5
52	8013		308.5

3X^2-2X+5

2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 7 7.5 8 8.5 9 9.5 10 10.5 11 11.5 12 12.5 13 13.5 14 14.5 15 15.5 16 16.5 17 17.5 18 18.5 19 19.5 20 20.5 21 21.5 22 22.5 23 23.5 24 24.5 25 25.5 26 26.5 27 27.5 28 28.5 29 29.5 30 30.5 31 31.5 32 32.5 33 33.5 34 34.5 35 35.5 36 36.5 37 37.5 38 38.5 39 39.5 40 40.5 41 41.5 42 42.5 43 43.5 44 44.5 45 45.5 46 46.5 47 47.5 48 48.5 49 49.5 50 50.5 51 51.5 52 13 18.75 26 34.75 45 56.75 70 84.75 101 118.75 138 158.75 181 204.75 230 256.75 285 314.75 346 378.75 413 448.75 486 524.75 565 606.75 650 694.75 741 788.75 838 888.75 941 994.75 1050 1106.75 1165 1224.75 1286 1348.75 1413 1478.75 1546 1614.75 1685 1756.75 1830 1904.75 1981 2058.75 2138 2218.75 2301 2384.75 2470 2556.75 2645 2734.75 2826 2918.75 3013 3108.75 3206 3304.75 3405 3506.75 3610 3714.75 3821 3928.75 4038 4148.75 4261 4374.75 4490 4606.75 4725 4844.75 4966 5088.75 5213 5338.75 5466 5594.75 5725 5856.75 5990 6124.75 6261 6398.75 6538 6678.75 6821 6964.75 7110 7256.75 7405 7554.75 7706 7858.75 8013

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