Answer:

4.25

Step-by-step explanation:

What is the next in sequence 1.25, 2, 2.75, 3.5,...?

-First, get the common difference (d)

a2-a1=2-1.25=0.75

-Add the common difference to the preceding term to get the next term

a4+d=3.5+0.75=4.25

Thus, the next term of the sequence 1.25, 2, 2.75, 3.5,... is 4.25.