Answer
$30, 919$.
Work Step by Step
The nth term of the arithmetic sequence is given by:
$a_n=a_1+(n-1) d \\ 558=73+5(n-1) \\ 97 =(n-1) \\ n= 98$
We see that there is a constant difference between the terms of $d=5$ and the terms are part of an arithmetic sequence.
The terms of the sum are the first $98$ terms of an arithmetic sequence, starting with $a_{1}=73$ and with a difference of $d= 5$.
The sum of the arithmetic sequence is given by:
$S_{n}= \dfrac{n}{2}\left(a_{1}+a_{n}\right)$
Now, $S_{98}= \dfrac{98}{2}[73+558] \\=(49)(631) \\=30, 919$
Therefore, the sum of the arithmetic sequence is: $30, 919$.