q = 0.16: S_2/S_3 = 0.97202, S_4/S_3 = 0.96995
sign +1: worst relative margin +0.00064 at a1 = 0.5738, a2 = 0.5738
    margin +0.00064  a1 = 0.5738  a2 = 0.5738
sign -1: worst relative margin +0.01395 at a1 = 0.1000, a2 = 0.0200
