#### Answer

$a_n=7(4)^{n-1}$
$a_4=448$

#### Work Step by Step

We are given:
$a=7, r=4$
We know that a geometric sequence has the form:
$a_{n}=ar^{n-1}$
$a_n=7(4)^{n-1}$
Thus:
$a_4=7* 4^{3}=448$

Published by
Brooks Cole

ISBN 10:
1305115546

ISBN 13:
978-1-30511-554-5

$a_n=7(4)^{n-1}$
$a_4=448$

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