Answer:
11, 14, 17, 20
Step-by-step explanation:
An arithmetic sequence has a common difference d between consecutive terms.
Consider 2, 6, 18, 54
6 - 2 = 4, 18 - 6 = 12, 54 - 18 = 36 ← no common difference, not arithmetic
Consider 3, 6, 12, 24
6 - 3 = 3, 12 - 6 = 6, 24 - 12 = 12 ← no common difference, not arithmetic
Consider 11, 14, 17, 20
14 - 11 = 3, 17 - 14 = 3, 20 - 17 = 3 ← common difference of 3, so arithmetic
Consider 7, 11, 13, 18
11 - 7 = 4, 13 - 11 = 2, 18 - 13 = 5 ← no common difference, not arithmetic
The arithmetic sequence is 11, 14, 17, 20
