The image shows a vector P with components. From the diagram, P has a horizontal component of 4 units and a vertical component of 3 units. The magnitude of vector P is calculated using the Pythagorean theorem:

$\left|P\right|=\sqrt{4^2+3^2}=\sqrt{16+9}=\sqrt{25}=5$

Therefore, the magnitude of vector P is 5 units.

Final Answer: 5