How do you find the sum of the infinite geometric series a1= 343, r=7, and a4= -1?

1 Answer

S=300.125

Explanation:

For what I can see from the problem. The number sequence may probably be like as follows;

343 -49 7 -1

in this case, r= -1/7

and a_1=343 and a_4=-1

The formula for Sum of infinite geometric series with 0<r<1 is

S=a_1/(1-r)

S=343/(1--1/7)=343/(8/7)=2401/8=300.125

God bless....I hope the explanation is useful.