Calculus
# Sequences and Series

Given that the first, second, and third terms of a geometric progression are:

$3, 9, 27 ... ,$

what is the fifth term?

If the six numbers

$7, k_1, k_2, k_3, k_4, \frac{7}{32}$

form a geometric sequence in this order, what is $k_2?$

Given that the third, fourth, and fifth terms of a geometric progression are:

$\ldots, 45, 135, 405, \ldots,$

what is the second term?