To find the midpoint of the segment PQ, where $P = (-3, 5)$ and $Q = (1, 9)$, we use the midpoint formula:

$M = \left( \frac{x_1 + x_2}{2}, \frac{y_1 + y_2}{2} \right)$

Substitute the coordinates of $P(x_1, y_1) = (-3, 5)$ and $Q(x_2, y_2) = (1, 9)$ into the formula:

$M = \left( \frac{-3 + 1}{2}, \frac{5 + 9}{2} \right)$

Now, let's calculate:

$M = \left( \frac{-2}{2}, \frac{14}{2} \right) = (-1, 7)$

So, the midpoint of segment $PQ$ is $M = (-1, 7)$.

Would you like more details on this process or have any additional questions?

Here are five related questions for further practice:

1. What is the formula to find the distance between two points in a plane?
2. How would the midpoint change if $P = (1, 5)$ and $Q = (-3, -9)$?
3. Can you find the slope of the line passing through points $P$ and $Q$?
4. How do you find the equation of the line passing through two points?
5. How does the midpoint formula apply in three-dimensional space?

Tip: The midpoint formula always gives the point that is equidistant from both endpoints of the segment. It is a useful tool in geometry for finding the center of a line segment.