The sequence is a Geometric Sequence.
The formula of a geometric sequence is given to be:
[tex]a_n=a_1r^{n-1}[/tex]where a₁ is the first term of the sequence, and r is the common ratio.
The common ratio is calculated to be:
[tex]\begin{gathered} r=\frac{a_2}{a_1}=\frac{4}{8} \\ r=\frac{1}{2} \end{gathered}[/tex]and the first term is:
[tex]a_1=8[/tex]Therefore, the formula for the nth term is given to be:
[tex]a_n=8(\frac{1}{2})^{n-1}[/tex]