Answer :
Final answer:
The complement of the event 'at least 84 of the 250 phone batteries were defective' is that fewer than 84 batteries were defective. The correct answer is b).
Explanation:
In the context of the question, the event is 'at least 84 of the 250 phone batteries were defective', which means 84 or more batteries were defective.
So, the complement of this event would be that fewer than 84 batteries were defective, since it is the only scenario that does not overlap with 'at least 84' being defective.
Therefore, the correct answer to the question: The complement of the event "at least 84 of the 250 phone batteries were defective" is fewer than 84 batteries were defective.
A battery is a device that stores energy and then discharges it by converting chemical energy into electricity. Typical batteries most often produce electricity by chemical means through the use of one or more electrochemical cells.
