#### Answer

geometric sequence
$\frac{1}{t}$

#### Work Step by Step

We are given:
$t^{3}, t^{2}, t, 1$, ...
We can see that this is a geometric sequence by dividing the terms:
$\displaystyle \frac{a_2}{a_1}=\frac{t^2}{t^3}=\frac{1}{t}$
$\displaystyle \frac{a_3}{a_2}=\frac{t}{t^2}=\frac{1}{t}$
$\displaystyle \frac{a_4}{a_3}=\frac{1}{t}$
Thus $r=\frac{1}{t}$. So the 5th term is:
$a_{5}=a_{4}*r=1*\frac{1}{t}=\frac{1}{t}$