To find the mean number of pets in the line plot, we first need to write down the numbers that the x's represent:
2, 4, 2, 4
Next, we add the numbers together: 2 + 4 + 2 + 4 = 12
Then, we divide by the number of x's: 12 รท 4 = 3
Therefore, the mean number of pets is 3.