Consider a pair of discrete random variables (X₁ ,X₂) with pmf given below. The range of X₁​ is {1,4,7,8} and that of X₂ is {8,9}.

1 4 7 8
8 0.14 0.27 0.04 0.16
9 0.2 0.07 0.09 0.03

a) What is the pmf of the distribution of X₂​ conditional on X₁​=7 evaluated at k2​=9 (in symbols: f2∣1​(9∣7)=P(X₂=9∣X₁​=7) )?