# What is the common ratio of this geometric sequence 1.1, 4.4, 17.6, 70.4,...?

Apr 23, 2016

4

#### Explanation:

since
$4 = \frac{4.4}{1.2} = \frac{17.6}{4.4} = \frac{70.4}{17.6} = - - -$

Apr 23, 2016

r = 4

#### Explanation:

For the standard geometric sequence:

$a , a r , a {r}^{2} , a {r}^{3} , \ldots \ldots . . , a {r}^{n - 1}$

where a represents the 1st term , r the common ratio.

$r = \frac{a r}{a} = \frac{a {r}^{2}}{a r} = \ldots \ldots . . \frac{a {r}^{n}}{a {r}^{n - 1}}$

For the sequence here , therefore

$r = \frac{4.4}{1.1} = \frac{17.6}{4.4} = 4$