In relation to the measurement from Cz to T4, how far is T5 if T5 is 3.5 cm closer to Cz than T4?

To understand the correct answer, it's important to establish the positions of Cz, T4, and T5 on the international 10-20 EEG system, which is commonly used for electrode placement in EEG studies.

Cz is the central reference point, while T4 is located at a defined distance from Cz. If T5 is positioned 3.5 cm closer to Cz than T4, we need to first know the distance from Cz to T4, since T5's position is relative to T4.

The point T4 is usually specified as being at a certain distance (typically around 5 cm) from Cz. Therefore, if T5 is 3.5 cm closer to Cz than T4, the measurement of T5 from Cz can be calculated by subtracting the 3.5 cm from the distance between Cz and T4. Thus, if T4 is, for example, at 5 cm from Cz, T5 would be at 5 cm - 3.5 cm = 1.5 cm from Cz.

Assuming a standard placement with typical distances, if T4 is at 5 cm, then the distance from Cz to T5 will indeed yield the answer as 1.5 cm from