Question

6 7 10 4 13 Xi Vi 50 50 40 60 30 (a) Choose the correct scatter diagram with x on the horizontal axis 60 60 50 50 40 40 30 20 10 30 20 10 10 15 10 15 (iv) 60 60 50 50 40 30 20 10 40 30 20 10

Answer 1

1. Scatter Diagram iv is the correct diagram depicting relationship between y and x.

2. Scatter Diagram shows that there is negative linear relationship between y and x.

3.

Sample Covariance,

x = [ 6,7,10,4,13]

y = [50,50,40,60,30]

Mean(x) = (6+7+10+4+13)/5 = 8

Mean(y) = (50+50+40+60+30)/5 = 46

Sample Covariance = (Sum_{i= 1- n} [(x_i - x_m)(y_i - y_m)]) n -1

Sample Covariance = -40

4.

Correlation(r) = NΣXY - (ΣX)(ΣY) / Sqrt([NΣX² - (ΣX)²][NΣY2 - (ΣY)²])

Putting Values of x and y,

x = [ 6,7,10,4,13]

y = [50,50,40,60,30]

Correlation = -0.99