at a light bulb factory, a batch of light bulbs is rejected if more than 5% of the bulbs in a sample taken from the batch are defective.

Question

If 240 bulbs are tested and eight are defective, will the batch be rejected ? Show your calculations

Answer 1

5% of 240=0.05*240=12, but only 8 are defective, so they are not rejected

or,...

8/240=1/30=0.0333333...=3.3333...%=3 1/3 % which is less than 5%