Question

For a bivariate data if E(x) = 5, E(y) = 3, E(x²) = 45, E(y²) = 85 and E(x) = 18. Find yxy

Answer 1

so, Var (x) = E(x²) = [E(x)]² 

= 45 – (5)² 

= 45 – 25 = 20

Var (y) = E(y²) – [(y)]² 

= 85 – (3)² = 85 – 9 

= 76 COV (x, y) 

= E(xy) – E(x) . E(y) 

= 18-5 x 3 

= 18- 15 = 3