Chapter 2 - Describing Distributions with Numbers - Chapter 2 Exercises - Page 70: 2.40b

$0, 0, 10, 10$

The deviation for two of the same number is zero (e.g. $3-3 = 0$). We are looking for the largest possible deviation, so we can achieve this by finding the largest differences (from the mean) possible. The largest possible difference is 10, (from $10-0$), so we would want this difference twice. Thus, the set will have the data points $0, 0, 10, and 10$.