Respuesta :

Geometric series have the same ratio. The series which is a geometric series is 1, 3, 9, 27.

What is a geometric series?

A series of numbers is a geometric series if the quotient of any two consecutive numbers is the same.

A series of numbers is a geometric series if the quotient of any two consecutive numbers is the same.

A.) 0.1 0.3 0.5 0.7

To check if the series is geometric series, find the quotient.

[tex]r_1=\dfrac{0.3}{0.1} = 3\\\\r_2 = \dfrac{0.5}{0.3} = 1.66[/tex]

Since the ratio is different this is not a geometric series.

B.) 1 3 9 27

To check if the series is geometric series, find the quotient.

[tex]r_1=\dfrac{3}{1} = 3\\\\r_2 = \dfrac{9}{3} = 3[/tex]

Since the ratio is the same this is a geometric series.

C.) 19 17 15 13

To check if the series is geometric series, find the quotient.

[tex]r_1=\dfrac{17}{19} = 0.8947\\\\r_2 = \dfrac{15}{17} = 0.8823[/tex]

Since the ratio is different this is not a geometric series.

D.) 0.4 0.9 1.5 2.2

To check if the series is geometric series, find the quotient.

[tex]r_1=\dfrac{0.4}{0.9} = 0.4444\\\\r_2 = \dfrac{0.9}{1.5} = 0.6[/tex]

Since the ratio is different this is not a geometric series.

Learn more about Geometric Series:

https://brainly.com/question/4617980

Answer:

its b 1 + 3 + 9 + 27

Step-by-step explanation: