Question

Ned is designing an experiment to test which hand sanitizer kills the most E. coli bacteria. In order for Ned's results to be valid, what must he do?

THE SUBJECT IS SCIENCE

Answer 1

need more info please 

Answer 2

So the correct answer is "Test the hand sanitizers on bacterial colonies that are kept in the exact same environmental conditions, such as temperature and light level"

Step-by-step explanation:

There are several ways to make sure the results of an investigation are valid. First, you and others can try to repeat the experiment. In addition, if it is a controlled experiment, you can make sure you have a control, only one independent variable, at least one dependent variable, and constants.

For Ned's results to be valid, he needs to test the hand sanitizers on bacterial colonies that are kept in the exact same environmental conditions, such as temperature and light level.