What is the weight of the heaviest person?

Answer the questions based on the following data:   Among the six persons D, E, F, G, H and I each have different weight. D is heavier than 3 persons, F is lighter than H. G is lighter than only E. F is not the lightest. The person who is third lightest is four times of the weight of the person who is the lightest in the group. The weight of lightest person is one third of the second lightest person, whose weight is 42 kg. The second heaviest person is of 74 kg. The weight of third heaviest person is a square number which lies in between the second heaviest person’s weight and fourth heaviest person’s weight. The weight of the heaviest person is a prime number less than 82 kg.