Question

Consider the following sample data for two variables. x y 7 7 8 5 5 9 3 7 9 7 Calculate the sample covariance. b. Calculate the sample correlation coefficient. c. Describe the relationship between x and y.

Answer 1

a) Sample co-variance = -1.5

b) Sample correlation = -0.4404152

c) Weak negative relationship between X and Y.

Explanation:

a) by sample co-variance = sum ((x - xbar)* (y-ybar)/n-1

#.... use the following program in R

x = c(7,8, 5, 3, 9)

y = c(7,5,9,7,7)

sv = sum((x-mean(x))*(y-mean(y)))/4

cor(x,y)

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