Let's solve the reflection problem step by step:

1. Identify the coordinates of $E$:

   • Point $E$ is marked at (2, 4) on the graph. So, the coordinates of $E$ are $(2, 4)$.

2. Reflect $E$ over the $y$-axis:

   • When reflecting a point over the $y$-axis, the $x$-coordinate changes sign, while the $y$-coordinate remains the same.
   • The reflection of point $E(2, 4)$ over the $y$-axis will be $E'(-2, 4)$.

3. Fill in the blanks:

   • Coordinates of $E$: $(2, 4)$
   • Coordinates of $E'$: $(-2, 4)$
   • When a point is reflected over the $y$-axis, the $x$-coordinate changes sign.

Do you want more details, or do you have any questions? Here are some related questions to explore:

1. How do you reflect a point over the $x$-axis?
2. How would you reflect a point over both the $x$- and $y$-axes?
3. What would happen if you reflect a point over the origin?
4. How do reflections relate to symmetry in geometry?
5. What are the general rules for reflecting a point over any line?

Tip: When reflecting over the $y$-axis, only the sign of the $x$-coordinate changes, while the $y$-coordinate remains the same.