From the paper: "Routing with Confidence: A Model for Trustworthy Communication"
Definition 6.7. Minimum Variance Simple-Path Problem (MVSPP) : Given a graph G = (V, E), with positive vertex weights w(v) for each vertex v ∈ V , and nonadjacent vertices s, t ∈ V , find an s, t -path p that minimizes the variance of weights for the set of vertices in p .
We assume that s, t are not directly connected by a single edge, because then the solution is trivial. The path 〈s, t〉 has variance 0 and is the minimum variance path.
Theorem 6.8. The Minimum Variance Simple-Path Problem (MVSPP) is NP- hard.
This is what i found out... I think that this answers my question.