When the Wright brothers designed their aircraft, they built a wind tunnel to model the aerodynamics of different wing designs. Identify each of the factors below as endogenous or exogenous to the Wright brothers' model.

Endogenous factors (variables that can be controlled when performing a model test):

aircraft speed wing angle

The Wright brothers used the wind tunnel to improve the design of their aircraft's wings.

Exogenous factors (variables that cannot be controlled when performing a model test):

wind and rain air pressure

No one can control the climate.