Question

A battery manufacturer randomly tests 500 batteries and finds that 3 are defective.

How many defective batteries would be expected in a shipment of 12,000 batteries?









A.
120







B.
72







C.
60







D.
36

Answer 1

To find this answer, we must first find the percentage of batteries that are defective. We can do this by dividing 3 by 500.

3 / 500 = 0.006

So our percentage of defective batteries is 0.6%.

Now, to find out how many defective batteries would be in a batch of 12000, we just need to multiply the constant (percentage of defective batteries) by the amount in the new batch.

12000 * 0.006 = 72

In a shipment of 12,000 batteries, 72 will be defective, so the correct answer choice would be B.
Hope that helped =)