Any number can be an arithmetic mean. SO just pick any three numbers between -2 and 12.
And if you want to find a set of numbers for which your selected number is a mean add 1 and subtract 1 from it, or add 2 and subtract 2 from it (or do both).
Suppose you pick 8.
Add 1 and subtract 1: 7 and 9. 8 IS the arithmetic mean of 7 and 9.
Add 2 and subtract 2: 6 and 10. 8 is the arithmetic mean of 6 and 10.
It is also the AM of 6, 7, 9 and 10.
28
16
30
12% = 0.12 In arithmetic, "of" usually means "times". 0.12 x 60 = 7.2
9
28
16
30
The sequence 216 12 23 is neither arithmetic nor geometric.
12% = 0.12 In arithmetic, "of" usually means "times". 0.12 x 60 = 7.2
12. Three thirds is equal to 3/3 which is 1. This means that 12/1=12
9
Arithmetic
It is neither.
The sequence in the question is NOT an arithmetic sequence. In an arithmetic sequence the difference between each term and its predecessor (the term immediately before) is a constant - including the sign. It is not enough for the difference between two successive terms (in any order) to remain constant. In the above sequence, the difference is -7 for the first two intervals and then changes to +7.
12, 6, 0, -6, ...
In modulo 12 arithmetic.