Question

How do you find the 100th partial sum of the arithmetic sequence `a_1=15, a_100=307`?

Answer 1

`S_100=16,100`

See below

Explanation:

The partial sum formula for a arthmetic sequence is

`S_n=((a_1+a_n)·n)/2`. Thus we have

`S_100=((15+307)·100)/2=16100`