The equations and domains of the stepladders are as follows:
- For the first stepladder: \(f(x) = 1.375x\) with domain \([0, 4]\)
- For the second stepladder: \(g(x) = 1.375x\) with domain \([0, 6]\)
The transformation indicates that the second stepladder is a scaled version of the first with a slope ratio of \(1.0\).
\[
\boxed{f(x) = 1.375x, \quad g(x) = 1.375x}
\]