Question

Use a calculator to find the correlation coefficient of the data set. PLEASE HELP!

Answer 1

The correlation coefficient of the data set is -0.901

Explanation:

x y xx xy yy

1 20 1 20 400

3 14 9 42 196

5 10 25 50 100

9 6 81 54 36

15 4 225 60 16

`\sum x = 1+3+5+9+15=33\\\sum y =20+14+10+6+4=54\\\sum x^2 =1+9+25+81+225=341\\\sum y^2=400+196+100+36+16=748\\\sum xy=20+42+50+54+60=226`

Formula :
`(N \sum XY - (\sum X)(\sum Y))/(√(N\sum X^2 - (\sum X)^2)√(N \sumY^2 - (\sum Y)^2)))`

`= (5 (226) - (33)(54))/(√(5(341)- (33)^2)√(5 (748) - (54)^2))\\=-0.901`

So, Option D is true

Hence the correlation coefficient of the data set is -0.901