Find the mode of the following set of data: 5, 2, 9, 3, 5, 1, 7, 5, 4, 2, 5

Step 1 ：Step 1: List the data in ascending order: \(1, 2, 2, 3, 4, 5, 5, 5, 5, 7, 9\)

Step 2 ：Step 2: Determine which number(s) appear most frequently. In this case, the number \(5\) appears most frequently.