Geometric Sequence and Means

Write the explicit formula for the following geometric sequence: 100, 50, 25, 12.5, ...

• a_n = 2(100)^n-1

• a_n = 100(2)^n-1

• a_n = 100(1/2)^n-1

• a_n = (1/2)(100)^n-1

Find the 9th term in the following geometric sequence:

4, 8, 16, 32, ...

• 384

• 512

• 768

• 1,024

Find a₁₂ in the following geometric sequence:

-1, -3, -9, -27, ...

• -177,147

• -19,683

• -59,049

• 118,098

Find a₁₁ in the following geometric sequence:

• -4,096

• -¹/₂₅₆

• -3,072

• -236,196

Find the common ratio of the following geometric sequence:

2, -10, 50, -250, ...

• r = -5

• r = 3

• r = 5

• r = -3

Find the 6th term of the following geometric sequence:

2, 8, 32, 128, ...

• 8192

• 2048

• 512

• 128

Insert three geometric means between 3 and 243.

• 9,27,81

• 81,27,9

• 81,27,3

• 9,18,27

Insert a geometric mean in the geometric sequence:

2, 8, ___, 128,...

The next term of the geometric sequence

4, 16, 64, ...

is

• 256

• 132

• 120

• 150

What is the common ratio for the following sequence:

3, 15, 75, 375, ...

• 12

• 1/5

• 5

• 3