Calculate the distance from A to B along a parallel of latitude, given their coordinates and Earth's radius.

Here are the solutions to questions 4 and 5:

Question 4:

a)

i) To calculate the distance from A to B along a parallel of latitude:
Points: A ($50^\circ N, 30^\circ E$), B ($50^\circ N, 150^\circ W$)
Latitude $\alpha = 50^\circ$.
Radius of Earth $R = 6370$ km.
$\pi = \frac{22}{7}$.

Step 1: Calculate the difference in longitude ($\Delta \theta$).
Since one longitude is East and the other is West, we add them.

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