Question

How do you find `S_n` for the arithmetic series given `a_1=43`, `a_n=115` and n=19?

Answer 1

`s_19 = 1508`

Explanation:

We can use the formula `s_n = n/2(t_1 + t_n)` to find the sum.

`s_19 = 19/2(43 + 115)`

`s_19 = 19/2(158)`

`s_19 = 1508`

Hopefully this helps!