What is the most difficult part of a controlled experiment?
testing only one variable
Otesting zero variables
Otesting multiple variables
testing two variables



Answer :

Final answer:

Controlled experiments test one variable while keeping others constant, with testing multiple variables posing challenges in isolating individual impacts.


Explanation:

Controlled experiments involve testing one variable while keeping other factors constant. The most difficult part of a controlled experiment is testing multiple variables because doing so makes it challenging to determine the specific impact of each individual variable.


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