What type of experiment is typically used to estimate the parameters of the model: y- bo +bx1+b2x2+b12x1x2+b3x?1+bax?2 Traditional experimentation, where process variables x and x, take on just 2 different values. A structured experiment where process variables x and x, take on at least 3 different values. None of the shown options. A experiment where all combinations of the process variables x and xy are considered but when x, and x, have just two different values.