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? a. test each hand sanitizer on different days and at different times of the day b. test the first brand of hand sanitizer on e. coli bacteria, then test the second brand of hand sanitizer on a sterilized petri dish c. test the hand sanitizers on bacterial colonies that are kept in the exact same environmental conditions, such as temperature and light level d. test the hand sanitizers first on e. coli bacteria and then on other bacterial species

test the hand sanitizers on bacterial colonies that are kept in the exact same environmental conditions, such as temperature and light level

the answer is; comparing the frequency of collisions with and without the device

this makes the anti-collision system an independent variable and the collisions a dependent variable. if there are fewer collisions with an anti-collision system that without, then it can be stated that the system is a success. essentially, collisions under an anti-collision system are compared with the frequency of collisions by cars with the human drivers.

the statement is true