Question

ace the assessment! – ssa practice item (sc.7.n.1.4)
directions: choose the letter of the most correct answer (see slide slide). record the letter in the space below
a group of students is conducting an experiment that models the effect of the size of a star on apparent magnitude. the students place three glowsticks 30 meters away. the glowsticks have the same brightness but are different sizes. they turn the lights off in the room and observe them. they observe that the larger the glowstick, the brighter it appears. they conclude that if two stars have the same absolute brightness, the larger one will appear brighter when viewed from earth.
what is the test variable (independent variable) in the experiment? _______________

Explanation:

To determine the independent variable, we analyze the experiment: the students change the size of the glowsticks (while keeping brightness and distance constant) to observe the effect on apparent magnitude. The independent variable is the factor manipulated by the experimenter, which here is the size of the glowstick (or the size of the star, as the glowsticks model stars).

Answer:

The size of the glowstick (or the size of the star being modeled)