Based upon the results of regular medical check-ups in a hospital, it was found that out of 1000 people, 700 were very healthy, 200 maintained average health and 100 had a poor health record. Let $A_1$ : People with good health, $A_2$ : People with average health, and $A_3$ : People with poor health. During a pandemic, the data expressed that the chances of people contracting the disease from category $A_1$, $A_2$ and $A_3$ are 25%, 35% and 50%, respectively. Based upon the above information, answer the following questions : (i) A person was tested randomly. What is the probability that he/she has contracted the disease ? (ii) Given that the person has not contracted the disease, what is the probability that the person is from category $A_2$ ?