=+40. The article “Sensitivity Analysis of a 2.5 kW Proton Exchange Membrane Fuel Cell Stack by Statistical Method” (J. of Fuel Cell Sci. and Tech., 2009: 1–6)

used regression methodology to investigate the relationship between fuel cell power (W) and the independent variables x1 5 H2 pressure (psi), x2 5 H2 flow

(stoc), x3 5 air pressure (psi), and x4 5 airflow (stoc).