Question

A factory produced 5,000 light bulbs. The manager selects a random sample of 120 light bulbs to check for defects. He finds that 3 light bulbs are defective. How many light bulbs out of 5,000 should the manager predict to be defective?

Answer 1

Total number of bulbs produced=5000
total number of samples=120
number of defective=3
Probability that a bulb selected at random is defective will be:
3/120=0.025

The total number of bulbs that could be defective out of 5000 bulbs produced will be:
5000(0.025)=125 bulbs