Answer:
15
Step-by-step explanation:
Terms in a geometric series that are n apart will have a ratio that is r^n. Here we have terms a4 and a1, which are 4-1=3 apart, so their ratio is ...
a4/a1 = 135/5 = 27 = r^3
r = ∛27 = 3
The second term is the first, multiplied by this common ratio:
a2 = a1·r = 3(5)
a2 = 15
