What is the distance from the left pre-auricular point to T3 if the distance from pre-auricular point to pre-auricular point is 36 cm?

To find the distance from the left pre-auricular point to T3, it’s essential to understand how the measurements are derived based on established standards for electrode placements, particularly in EEG setups and related fields in sleep technology.

The standard distance between the two pre-auricular points is often used as a reference in various applications, including electroencephalography (EEG) and sleep studies. In this case, if the distance between the two pre-auricular points is 36 cm, T3 is typically positioned at a certain percentage of that distance from the left pre-auricular point.

Generally, T3 is located at 20% of the total distance from the left pre-auricular point toward the midline of the head. To calculate this, you can take 20% of 36 cm.

Calculating this gives:

0.20 x 36 cm = 7.2 cm

Thus, the distance from the left pre-auricular point to T3 would be 7.2 cm. However, in this question, the answer provided isn't aligned with that calculation. It suggests that to find the distance from the left pre-auricular point to T3 directly, the problem has to take into account