Lines 1-15 (1) In the lab, a student team tested how quickly different fabrics dried after being soaked. (2) They weighed each sample, submerged it for one minute, and then hung it under the same fan. (3) Every five minutes, they recorded the mass again. (4) At first, the data seemed messy: two cotton samples lost water at different rates. (5) Their instructor asked whether anything besides fabric type had changed. (6) After a pause, one student noticed that the thicker cotton had been folded over the hanger, creating a double layer. (7) The fold reduced airflow and slowed evaporation. (8) "So the fabric isn't the only variable," the instructor said. (9) "The setup introduced a confounding factor." (10) She explained that a confounding factor is something that varies along with the variable being tested and can mislead you about the true cause. (11) The students refolded the samples so each hung in a single layer. (12) This time, the cotton pieces behaved similarly. (13) The group revised its notes, relieved that the pattern now made sense. (14) "Science," the instructor added, "often means finding what you accidentally changed." (15) The students laughed, then checked their clips again.
As it is used in the passage (underlined), the word confounding most nearly means:
- predictable
- comforting
- misleading (correct answer)
- celebratory
Explanation: In this context, "confounding" means misleading or causing confusion in the results. The instructor explains that "a confounding factor is something that varies along with the variable being tested and can mislead you about the true cause," directly defining it as something that creates false or unclear conclusions. The folded cotton fabric misled the students about the drying rates because it introduced an uncontrolled variable. Choice A (predictable) doesn't fit since confounding factors create unpredictability and unclear results in experiments.