1 Answer

Nils Ohlmeier · Answer 1 · 2022-03-24T00:42:17+0000

Answer:

No. The sequence is not arithmetic, but rather geometric.

Explanation:

Arithmetic Sequence

Arithmetic Sequence is a sequence that has common difference.

To find a common difference:-

$\displaystyle \large{a_(n + 1) - a_n = d}$

Thus:-

20-100 = -80

4-20 = -16

Since both are not common, the sequence is not arithmetic.

Geometric Sequence is a sequence that has common ratio.

To find a common ratio:-

$\displaystyle \large{ (a_(n + 1))/(a_n) = r}$

Thus:-

20/100 = 1/5

4/20 = 1/5

Since both are common, the sequence is geometric.

Let me know if you have any questions!