Shipment ------No. of Defective Chips/shipment---Total Chips in shipment
S2 -------------- 5 ------------------------ ----------------------12000
S3 -------------- 6 ----------------------------------------------- 18000
S4 -------------- 4 ----------------------------------------------- 16000
A computer chip manufacturer expects the ratio of the number of defective chips to be total number of chips in all future shipments equal to the corresponding ratio for shipmemts S1,S2,S3 and S4 comined as shown in the table above. What is the expected number J of defective chips in a shipment of 60000 chips?  Pick: A) 14 B) 20 C) 22 D) 24 E) 25
I agree with your solution = 20. But the question is:   There are different combination to get 60,000 chips. For example: 1*S3 + 2*S4 + 2*S2. In this way, we ship 60,000 chips with only   6 + 4*2 + 2*2= 
<gadget id="calculator">  6 + 4*2 + 2*2</gadget>
<output>18</output>
18 defective chips, better than the average of 20.   The question is to find the expected number J of defective chips, i guess it assume the minimum #, therefore it might not be 20.
<result>B</result>
Shipment ------No. of Defective Chips/shipment---Total Chips in shipment
S2 -------------- 5 ------------------------ ----------------------12000
S3 -------------- 6 ----------------------------------------------- 18000
S4 -------------- 4 ----------------------------------------------- 16000
A computer chip manufacturer expects the ratio of the number of defective chips to be total number of chips in all future shipments equal to the corresponding ratio for shipmemts S1,S2,S3 and S4 comined as shown in the table above. What is the expected number J of defective chips in a shipment of 60000 chips?