what is the value of the fourth term in a geometric sequence for which a 1 10 and r 0.5

Question

jhannybean · Answer

First off, what is the equation for the geometric sequence?

solomonzelman · Answer

$\large\color{black}{  a_1 =10}$ ,  $\large\color{black}{ r =0.5}$ 

there is a form for any nth term:     $\large\color{black}{  a_{n}=a_1\times r^{n-1}}$

solomonzelman · Answer

in your case, it is :   $\large\color{black}{  a_{4}=a_1\times r^{4-1}}$

                                       $\large\color{black}{ \Downarrow}$

                               $\large\color{black}{  a_{4}=a_1\times r^{3}}$

solomonzelman · Answer

you know the $\large\color{black}{a_1}$ and the $\large\color{black}{ r}$.
If you have questions, ask.