Answer:
Var(y|x = 25) = 24
Step-by-step explanation:
E(x)= 40 E(y) = 30
Var(x) = 76 Var(y) = 32
Var(x|y=28.5) = 57
(1-[tex]\rho^{2}[/tex])Var(x) = 57
(1-[tex]\rho^{2}[/tex])76 = 57
[tex]\rho^{2}[/tex] = 0.25
[tex]\rho[/tex] = 0.5
Var(y|x = 25) = (1-[tex]\rho^{2}[/tex])Var(y)
= (1-[tex]\0.5^{2}[/tex])32
= 0.75×32 = 24
Var(y|x = 25) = 24