Question

A study of bone density on 5 5 random women at a hospital produced the following results.

Age	37 37	41 41	49 49	61 61	65 65
Bone Density	350 350	335 335	325 325	320 320	315 315

Copy DataAge Bone Density 37 350 41 335 49 325 61 320 65 315

Step 3 of 3 :

Calculate the correlation coefficient, r. Round your answer to three decimal places.

Answer 1

Solution :

X	Y	XY	X^2	Y^2
37	350	12950	1369	122500
41	335	13735	1681	112225
49	325	15925	2401	105625
61	320	19520	3721	102400
65	315	20475	4225	99225

n	5
sum(XY)	82605.00
sum(X)	253.00
sum(Y)	1645.00
sum(X^2)	13397.00
sum(Y^2)	541975.00
Numerator	-3160.00
Denominator	3384.91
r	-0.9336
r square	0.8715
Xbar(mean)	50.6000
Ybar(mean)	329.0000
SD(X)	10.9105
SD(Y)	12.4097
b	-1.0618
a	382.7285

Correlation coefficient = r = -0.934