Suppose the county has 40% registered Mugwump voters. Furthermore, various surveys over the years have shown that in that county 90% of registered Mugwumps usually do vote for the Mugwump candidate. The Mugwump candidate for Governor is popular and (based on various polls) is even expected to get 30% of those voters who are not registered Mugwumps. On election day a voter after exiting the voting booth says (truthfully) that she has voted for the Mugwump candidate. What is the probability that she is a registered Mugwump?