Question

Find the geometric means in the following sequence.

Answer 1

Answer:

Last choice. d.

Step-by-step explanation:

We are given the first term and the sixth term.

The first term is $a_1=-9$.

The sixth them is $a_6=a_1r^5=-9216$.

Let's solve for the common ratio, r.

$-9r^5=-9216$

Divide both sides by -9:

$r^5=1024$

Take the fifth root of both sides:

$r=1024^{\frac{1}{5}}$

$r=4$

So the common ratio is 4.

$a_1=-9$

$a_2=-9(4)=-36$

$a_3=-9(4)^2=-144$

$a_4=-9(4)^3=-576$

$a_5=-9(4)^4=-2304$

$a_6=-9(4)^5=-9216$