A manufacturing firm receives shipment of parts from
two different suppliers from UK and Japan. Currently, 65% of the parts
purchased by the company are from supplier 1 (UK) and the remaining 35%
are from supplier 2 (Japan). The quality of the purchased parts varies with the
source of supply. Historical data suggest that the quality ratings of the two
suppliers are as shown below:
Percent of good parts Percent of bad parts
Supplier 1 98 2
Supplier 2 95 5
The parts from the two suppliers are used in the firm‟s manufacturing process
and during the processing a machine breaks down because it attempts to
process a bad part.
Required:
(i) Given the information that a part is bad, determine the probability that it
came from Supplier 1 and it came from Supplier 2. (10
marks)
(ii) Show the above information in a probability tree. (10
marks)