Squidward loves playing his clarinet and believes it attracts more jellyfish then any other instrument he has played. In order to test his hypothesis, Squidward played a song on his clarinet for a total of 5 minutes and counted the number of jellyfish he saw in his front yard. He played the song a total of 3 times on his clarinet and repeated the experiment using a flute and a guitar he also recorded the number of jellyfish he observed when he was not playing an instrument. The results are show in the chart.

10. What is the independent variable?