From a shipment of 350 light-bulbs, a sample of 70 was selected at random and tested. If 21 light-bulbs in the sample were found to be defective, how many defective light-bulbs would be expected in the entire shipment?

Answer 1

since you're sampling a fifth of the light-bulbs, then you would times 21 and 5 to get 105 defective light-bulbs

Answer 2

Since 70 bulbs is 1/5 of all the light-bulbs,then 21*5=105 will be defective.

Answer 3

its not that