Question

Determine the correlation coefficient, rounded to the nearest thousandth. x 12 14 13 17 18 20 y 30 10 10 9 6 6

Answer 1

Solution:

X	Y	XY	X^2	Y^2
12	30	360	144	900
14	10	140	196	100
13	10	130	169	100
17	9	153	289	81
18	6	108	324	36
20	6	120	400	36

n	6
sum(XY)	1011.00
sum(X)	94.00
sum(Y)	71.00
sum(X^2)	1522.00
sum(Y^2)	1253.00
Numerator	-608.00
Denominator	856.27
r	-0.7101
r square	0.5042
Xbar(mean)	15.6667
Ybar(mean)	11.8333
SD(X)	2.8674
SD(Y)	8.2949
b	-2.0541
a	44.0135

r = -0.710

The correlation coefficient r = -0.710