Find the Fourth Term 1/8 , 1/4 , 1/2

This is a geometric sequence since there is a common ratio between each term. In this case, multiplying the previous term in the sequence by ${\displaystyle 2}$ gives the next term. In other words, ${\displaystyle a_n=a_1{r}^{n-1}}$.

Geometric Sequence: ${\displaystyle r=2}$

This is the form of a geometric sequence.

Substitute in the values of ${\displaystyle a_1=\frac{1}{8}}$ and ${\displaystyle r=2}$.

Combine ${\displaystyle \frac{1}{8}}$ and ${\displaystyle 2^{n-1}}$.

Substitute in the value of ${\displaystyle n}$ to find the ${\displaystyle n}$th term.