The folding and unfolding rate constants for a myoglobin mutant have been determined. The unfolding rate constant kF → U = 3.62 × 10-s S-1 and the folding rate constant kU→F = 255 S-1, where F is the folded protein and U is the unfolded (denatured) protein. For wild-type myoglobin, Δ GUF′→U = + 37.4 kJ/mol. Which myoglobin is more thermodynamically stable, the mutant or the wild-type?