To find the distance between two points on the same parallel of latitude, we use the formula:

To find the distance between two points on the same parallel of latitude, we use the formula:

$$D = \frac{\theta}{360^\circ} \times 2\pi R \cos(\phi)$$

where:

• $\theta$ is the difference in longitudes.
• $R$ is the radius of the Earth.
• $\phi$ is the common latitude.
• $\pi$ is approximately 3.14.

From the problem statement, we are given:
Point P: $(27^\circ \text{N}, 6^\circ \text{W})$
Point Q: $(27^\circ \text{N}, 97^\circ \text{W})$
Radius of Earth $R = 6400 \text{ km}$ (from $z=6400$)
$\pi = 3.14$ (from $x=3.14$)