Question: how to calculate standard deviation of y-intercepts of regression lines?
Answer: Considering 3.3 times the standard deviation, we can calculate the Y-intercept of the LOD using the formula: yLOD = 3.3 σ + c and the LOD concentration (x) as x = (yLOD-c) / m. Combined, this results in x = 3.3 σ / m, which is the formula given above by the ICH.