GPA (4.0 scale) = GPA (6.0 scale) * (4.0 / 6.0)
In this case, a 5.5 GPA on a 6.0 scale would be equivalent to:
GPA (4.0 scale) = 5.5 * (4.0 / 6.0)
GPA (4.0 scale) = 3.67
Therefore, a 5.5 GPA on a 6.0 scale would be equal to a 3.67 GPA on a 4.0 scale.