The following is a set of data of sample size n11 X 7 5 4 16

The following is a set of data of sample size n=11

X: 7, 5, 4, 16, 6. 2, 15, 20, 10, 9, 1

Y: 21, 15, 12, 48, 18, 6, 45, 60, 30, 27, 3

Find the sample covariance and the coefficient of correlation.

Solution

There are two variables x and y

X: 7, 5, 4, 16, 6. 2, 15, 20, 10, 9, 1

Y: 21, 15, 12, 48, 18, 6, 45, 60, 30, 27, 3

Formula covariance of xy = E(xy) -E(x)E(y)

Variance of x = E(x^2)- xbar^2

r = Cov/sx sy

where sx and sy are std deviations of x and y.