Question

21. Use the least square method to determine the equation of line of best fit for the data by completing the following table and then plot the line. 24 120 1 649 100 121 36 2569 33 36 5 8 120 1 848 1나나 81 36 14 7 64 10 528 656 1312

Answer 1

	X	Y	X * Y	X2	Y2
	8	3	24	64	9
	2	10	20	4	100
	11	3	33	121	9
	6	6	36	36	36
	5	8	40	25	64
	4	12	48	16	144
	12	1	12	144	1
	9	4	36	81	16
	6	9	54	36	81
	1	14	14	1	196
Total	64	70	317	528	656

Equation of regression line is Ŷ = a + bX

((X3) – 2X3u)/(43X3 – XX3U) = 9


b= (10 * 317 – 64 * 70)/(10 * 528 – (64))

b = -1.106

a =( Σ Y - ( b * Σ X) ) / n
a =( 70 - ( -1.1064 * 64 ) ) / 10
a = 14.081
Equation of regression line becomes Ŷ = 14.0811 - 1.1064 X