`4,9,14,19,24`

A sequence is arithmetic when its terms continually increase or decrease by the same number called as the common difference.

So, let's find the common difference,

`a_2-a_1=9-4=5`

`a_3-a_2=14-9=5`

`a_4-a_3=19-14=5`

`a_5-a_4=24-19=5`

So the **terms are increasing by the common difference of 5 which shows that the sequence is arithmetic.**