Question

The following table shows data for the first several years of a small company's existence. The x is the years since it's founding and the y is the profit (in $100,000).

Find the linear regression line for the values. You will need to use a calculator, spreadsheet, or statistical software.

Enter your answer in the form y=mx+b, with m and b both rounded to two decimal places.

x	y
1	3.1
2	4.37
3	5.5
4	5.29
5	7.52
6	8.31
7	9.01

Answer 1

Solution :

X	Y	XY	X^2	Y^2
1	3.4	3.4	1	11.56
2	4.37	8.74	4	19.0969
3	5.5	16.5	9	30.25
4	5.29	21.16	16	27.9841
5	7.52	37.6	25	56.5504
6	831	4986	36	690561
7	9.01	63.07	49	81.1801

n	7
sum(XY)	5136.47
sum(X)	28.00
sum(Y)	866.09
sum(X^2)	140.00
sum(Y^2)	690787.62
Numerator	11704.77
Denominator	28297.33
r	0.4136
r square	0.1711
Xbar(mean)	4.0000
Ybar(mean)	123.7271
SD(X)	1.7078
SD(Y)	307.7541
b	59.7182
a	-115.1457

y = 59.72 x - 115.15