In order to determine the effectiveness of a new measles antibody test, it is administered to 500 people chosen at random. An older more elaborate test reveals that 425 of the people have the measles antibodies. The new test was positive when administered to 96% of those who have the antibodies and it also gave positive results in 2% of those who do not have them. Based on these results, what is the probability that a randomly chosen person has measles antibodies in his/her blood if the new test indicates their presence?