In a factory there are three types of Machines `M_1, M_2, M_3` which produces 2000, 2500 and 4000 bolts daily respectively. `M_1, M_2, M_3` produces 3%, 4%  and 2.5% defective products respectively. A bolt is drawn at random from the product and is found to be defective. What is the probability of that it is manufactured by machine `M_2`?