1.4.8. in a certain factory, machines i, ii, and iii are all producing springs of the same length. machines i, ii, and iii produce 1%, 4%, and 2% defective springs, respectively. of the total production of springs in the factory, machine i produces 30%, machine ii produces 25%, and machine iii produces 45%. (a) if one spring is selected at random from the total springs produced in a given day, determine the probability that it is defective. (b) given that the selected spring is defective, find the conditional probability that it was produced by machine ii.