If Cz to Pz measures 7.2 cm, what is the distance from T4 to Pz given that T4 is 4.2 cm from Cz?

To determine the distance from T4 to Pz, we can use the information about the distances provided in the question. The distance from Cz to Pz is 7.2 cm. Since T4 is located 4.2 cm from Cz, we can calculate the distance from T4 to Pz by subtracting the distance from Cz to T4 from the total distance from Cz to Pz.

In this case, you take the distance from Cz to Pz (7.2 cm) and subtract the distance from Cz to T4 (4.2 cm):

7.2 cm (distance from Cz to Pz) - 4.2 cm (distance from Cz to T4) = 3.0 cm.

This calculation shows that the distance from T4 to Pz is indeed 3.0 cm, which corresponds to the correct answer choice. The understanding of this concept hinges on the application of the distances measured in the EEG system, where the positions of electrodes are critical, and knowing the relationship between these positions allows for accurate distance calculations.