Answer
arithmetic sequence
common difference = $4$
Work Step by Step
You are given the sequence $3,7,11,15$.
Check to see if there is a common difference (the difference between consecutive terms) and if there is, the sequence would be arithmetic:
Here, we have:
$7-3=4\\
11-7=4\\
15-11=4$
The difference is $4$, which is a common difference, so the sequence is arithmetic.