Here are the differences for each pair: 5.5 - 5.55 = -0.05 5.7 - 5.75 = -0.05 5.6 - 5.5 = 0.1 5.5 - 5.4 = 0.1 5.85 - 5.7 = 0.15 5.55 - 5.6 = -0.05 5.4 - 5.35 = 0.05 5.5 - 5.35 = 0.15 5.15 - 5 = 0.15 5.8 - 5.7 = 0.1 5.2 - 5.1 = 0.1 5.55 - 5.45 = 0.1 5.35 - 5.45 = -0.1 5 - 4.95 = 0.05 5.5 - 5.4 = 0.1 5.55 - 5.5 = 0.05 5.55 - 5.35 = 0.2 5.5 - 5.55 = -0.05 5.45 - 5.25 = 0.2 5.6 - 5.4 = 0.2 5.65 - 5.55 = 0.1 6.3 - 6.25 = 0.05 Now, calculate the mean of these differences: Mean = (-0.05 - 0.05 + 0.1 + 0.1 + 0.15 - 0.05 + 0.05 + 0.15 + 0.15 + 0.1 + 0.1 + 0.1 - 0.1 + 0.05 + 0.1 + 0.05 + 0.2