Question

Consider the relationship between the number of bids an item on eBay received and the item's selling price. The following is a sample of 5 items sold through an auction.

Price In Dollars 120 150 160 180 190

Number Of Bins 12   15   16     17   18

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

Answer 1

X	Y	XY	X^2	Y^2
120	12	1440	14400	144
150	15	2250	22500	225
160	16	2560	25600	256
180	17	3060	32400	289
190	18	3420	36100	324

From the above table and formula we get the value are as:

n	5
sum(XY)	12730.00
sum(X)	800.00
sum(Y)	78.00
sum(X^2)	131000.00
sum(Y^2)	1238.00
Numerator	1250.00
Denominator	1260.95
r	0.991

the correlation coefficient, r. = 0.991