Find the explicit formula for the geometric sequence $a_n$ with the following

information given.

$a_1=10$

$a_4=\frac{10}{27}$

Select the correct answer below:

$a_n=10(\frac{2}{3}{)}^n$

$a_n=\frac{1}{3}(10{)}^n$

$a_n=10(\frac{2}{3}{)}^{n-1}$

$a_n=\frac{1}{3}(10{)}^{n-1}$

$a_n=10(\frac{1}{3}{)}^n$

$a_n=10(\frac{1}{3}{)}^{n-1}$