# Sequences and means

(See attached file for full problem description)

1. Find the sum of the finite geometric series to three decimal places.

9 n

Î£ - 3(0.5)

n=3

2. Write the first 5 terms of the specified sequence. Determine whether the sequence is arithmetic. If it is, find the common difference.

Problem is "a(sub n)" = "1 over n+3"

a = _1_

n n+3

3. Find the sum of the first 14 terms of the arithmetic sequence, if the first term is -4 and the common difference is 5.

4. Find three arithmetic means between -5 and -37.

5. Determine which of the four sequences below are geometric.

7,14,28,56,112,...

7,1,-5,-11,-17,...

7,8,9,11,12,...

7,-14,28,-56,112,...

https://brainmass.com/math/algebra/sequence-arithmetic-finite-series-91322

#### Solution Preview

Please see the attached file.

1. Find the sum of the finite geometric series to three decimal places.

9 n

Î£ - 3(0.5)

n=3

By a formula , we have

9 n

Î£ - 3(0.5)

n=3

= .............Take out a factor (-3)

= ........... Take out a factor (0.5)^3

.............Apply the formula with r=0.5 and n=6

2. Write the first 5 terms of the specified sequence. Determine whether the sequence is arithmetic. If it is, find the common difference.

...

#### Solution Summary

The problems in this set include geometric and arithmetic sequences and means. Which of the sequences are geometric are determined.