Solution of problem N3609 probability theory

Solution of problem N3609 probability theory

3609. Among the parts arriving at the assembly from the first machine, 0.2% are rejected, from the second - 0.3%, from the third - 0.25%, from the fourth - 0.4%. Their performance is 1: 3: 2: 4, respectively. Taken at random item was standard. Find the probability that it is made on the fourth machine.

Additional information:

Detailed solution. Decorated in Microsoft Word 2003 (Quest decided to use the formula editor)