Carcass wrote:
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’s the expected number of defective chips in a shipment of 60,000 chips?
A. 14
B. 20
C. 22
D. 24
E. 25
Let's find some TOTALS for all 4 shipments combined.
There are 51,000 chips altogether
There are 17 defective chips altogether.
So, 17/51000 of the chips are defective. (notice that 17 divides nicely into 51000!)
SIMPLIFY:
1/3000 of the chips are defectiveSo, if we have a shipment of 60,000 chips, 1/3000 of them will be defective.
(1/3000)(60,000) = 20 defective chips
Answer: B
Cheers,
Brent