4. Suppose two machines produce nails which are on average 10 inches long. A sample of 11 nails is selected from each machine. Machine A: 6, 8, 8, 10, 10, 10, 10, 10, 12, 12, 14 Machine B: 6, 6, 6, 8, 8, 10, 12, 12, 14, 14, 14 Which machine do you prefer? (0) Based on standard deviation and coefficient of variation