Question

Use the data values in the table below to calculate the correlation, r, between the variables x and y.

Hint: Use technology to do this...you do not need to compute this by hand.

x	y
1	17.98
2	21.56
3	25.84
4	27.72
5	27.4
6	29.18
7	33.56
8	32.44
9	35.82

Give your answer to rounded three decimal places.

Answer 1

Solution:

X	Y	XY	X^2	Y^2
1	17.98	17.98	1	323.2804
2	21.56	43.12	4	464.8336
3	25.84	77.52	9	667.7056
4	27.72	110.88	16	768.3984
5	27.4	137	25	750.76
6	29.18	175.08	36	851.4724
7	33.56	234.92	49	1126.2736
8	32.44	259.52	64	1052.3536
9	35.82	322.38	81	1283.0724

n	9
sum(XY)	1378.40
sum(X)	45.00
sum(Y)	251.50
sum(X^2)	285.00
sum(Y^2)	7288.15
Numerator	1088.10
Denominator	1124.36
r	0.9677
r square	0.9365
Xbar(mean)	5.0000
Ybar(mean)	27.9444
SD(X)	1.7078
SD(Y)	3.9250
b	2.0150
a	17.8694

r = 0.968