Question

Tell whether each sequence is arithmetic, geometric, or neither.

1. 32, 16, 8, 4, ... (1 point)
arithmetic
geometric
neither
2. 1, 4, 9, 16, ... (1 point)
arithmetic
geometric
neither
What is the common difference of each arithmetic sequence?
3. 16, 19, 22, 25, . . . (1 point)
-3
5
3
-5
4. 3, 5.8, 8.6, 11.4, . . . (1 point)
2.4
2.6
2.8
2.9
What is the common ratio of each geometric sequence?
5. 6, 24, 96, 384, . . . (1 point)
18
4
14
8
6. 12, 3, , , . . . (1 point)
1/4
4
3/4
6

Answer 1

1. geometric series
2. neither of them
3. common difference is 3
4. common difference is 2.8
5. the answer is 3/4

Answer 2

As an overview, an arithmetic series has a common difference (d) while a geometric series has a common ratio (r). Common difference is calculated by subtracting two consecutive numbers. Common ratio is calculates by dividing two consecutive numbers.

1.) Geometric series (r = 1/2)
2.) Neither
3.) d = 3
19 - 16 = 3; 22 - 19 = 3; 25 - 22 = 3
4.) d = 2.8
5.8 - 3 = 2.8; 8.6 - 5.8 = 2.8; 11.4 - 8.6 = 2.8
5.) r = 4
24/6 = 4; 96/24 = 4; 384/96 = 4
6.) r = 4
12/3 = 4