Answer:
-0.5, 2, 4.5, 7, 9.5
Step-by-step explanation:
The given terms are 6 apart, so the common difference is 1/6 of their difference:
d = (12 -(-3))/6 = 15/6 = 5/2 = 2.5
Add 2.5 to each term to get the next one. Then the sequence is ...
-3, -0.5, 2.0, 4.5, 7.0, 9.5, 12