4, 6, 9, 13.5 next three numbers

Question

Pattern:Each number is 1.5 times the previous number.

Each number is 3/2 of the previous number.

Answer 1

13.5 x 3/2 = 27/2 x 3/2 = 81/4 = 20 1/4 = 20.25

or

13.5 x 1.5 = 13.5 + 6.75 = 20.25

next number is 20.25 x 1.5 = 20.25 + 10.125 = 30.375

number after that = 30.375 x 1.5 = 30.375 + 15.1875 = 45.5625

it's a geometric sequence

the nth term = an=a1(r^n-1)

an = 4(1.5)^(n-1