Determine whether the given sequence is arithmetic. If so, then find the common difference. 4, 9, 14, 19, 24,...

From the above sequence, it can be observed that $a_1=4,a_2=9,a_3=14,a_4=19,a_5=24.$ Subtract the two consecutive numbers of the sequence as shown below: $a_2-a_1=9-4$
$=5$
$a3-a2=14-9$
$=5$
$a_4-a_3=19-14$
$=5$
$a_5-a_4=24-19$
$=5$ It can be seen that the difference between the two consecutive numbers of the sequence is 5 (a constant). Thus, the given sequence is arithmetic and the common difference is 5.