question: a group of students investigated how the length of a column of air inside a test tube. Pitch refers to how high or low a sound is. The length of the air column was varied by pouring different amounts of water into five test tubes. The pitch produced by each test tube was ranked on a scale of 1-5, with 1 being the lowest pitch and 5 being the highest pitch. The results of the investigation are shown in the data table below. IDENTIFY THE DEPENDENT VARIABLE * ahh please helpp