A computer chip manufacturer expects the ratio of the number of defective
chips to the total number of chips in all future shipments to equal the
corresponding ratio for shipments S1 S2 S3 and S4 combined, as shown in the
table above. What is the expected number of defective chips in a shipment of
60000 chips?
对应的图表： shipment number of defective chips in the
shipment total number of chips in the shipment
S1
2 5000
S2
5 12000
S3
6 18000
S4
4 16000
题目看不明白，谢谢了，哪位 帮个忙 | 
