Geometric Sequence and Means

Which variable represents the common ratio?

• r

• n

• a₁

• a_n

15, __, __, 405... What are the missing terms?

(Separate your answers with a comma and a space)

Ex: 6, 7

• 6

• 3

• 4

-3, __, -108... what is the common ratio?

• 4

• -3

• 6

• -6

All are the the geometric means between 3125 and 5 except....

• 1025

• 625

• 25

• 125

Find 2 geometric means between 2 and 128.

(Separate your answers with a comma and a space)

Which of the following is the common ratio of the geometric sequence

• 10

• 2

• 3

What are the three geometric means between \frac{2}{3}\ and\ \frac{2}{1875}?

Find the next three terms of the following geometric sequence:

4, 12, 36, 108, ...

• 324, 972, 2916

• 972, 2916, 8748

• 405, 1215, 3645

• 324, 648, 1296

Write the explicit formula for the following geometric sequence: 10, 20, 40, 80, ...

• a_n = 10(2)^n-1

• a_n = 2(10)^n-1

• a_n = 10(2)ⁿ

• a_n = 2(10)ⁿ