Answer:
0.2
Step-by-step explanation:
U need to count how many times it goes up and divide 0.4 by 2
x - 3.8 = y
3.8 - 3.8 = 0
4.2 - 3.8 = 0.4
5.1 - 3.8 = 1.3
7.3 - 3.8 = 3.5