Let us follow Dijkstra's Algorithm step by step till vertex E is deleted from the Q.
Assuming $vertex A$ as the source vertex, $decrease key()$ is performed on vertices $B,C and D$ and the keys in min-heap will be $\begin{Bmatrix} 2,15,23,\infty ,... \end{Bmatrix}.$. Vertex B is deleted from heap. Now $decrease key()$ is performed on $ E $ and $ F $ and the min heap will be $\begin{Bmatrix} 7,15,17,23,\infty ,... \end{Bmatrix}.$ Vertex F gets deleted from the min-heap.$Decrease key()$ is performed on vertices $E,H , G$ $ and C$ and the min-heap will be $\begin{Bmatrix} 11,13,23,36,7+y,\infty ,... \end{Bmatrix}.$ .
Definitely $7 + y > 11$, or else parent of $H$ would be $F$. Following similar steps after vertex E gets deleted the new key for $H$ is $19( =11(=7+4) + 8)$ with $parent E$. It certainly means that $x$ is $8$. Also because parent of $H$ is $E$ it means $7 + y > 19$. But I dont think we can pin point what $y$ will be exactly.