Hi,

Can we draw a graph when some of our regression coefficients show up as insignificant?
Specifically, I have estimated a quadratic moderation relationship in which only the interaction effect and the coefficient of the independent variables were significant. Then I wanted to plot a curve using the Johnson-Neyman toolbox

Consider for example these two equations:
Eq 1. Y = a + b1*X + b2*X^2 + e
Eq 2. Y = a + b1*X + b2*X^2 + b3*W + b4*X*W + b5*X^2*W + e
where, Y is DV (Dependent Variable), X is IV (Independent Variable), and W is the moderator.

I really doubt whether I can plot these equations when b1 is insignificant in Eq1, and b2, b3, and b4 are insignificant in Eq2.
I understand that the above questions include separate issues. First, I don't want to use the result of this discussion for the matter of inference. It is just for representing a graph to facilitate communication. Second, Equations 1 and 2 are different, apparently. However, the issue is if we are going to insert data into variable X, can are we allowed to do it for terms whose coefficients are insignificant?

Thank you in advance.