Question

Find the sum

4
Σ(0.5)^n
n=0

Answer 1

= .5^0 + .5^1 + .5^2 + .5^3 + .5^4

= 1 + .5 + .5^2 + .5^3 + .5^4
or
= 1 + 1/2 + (1/2)^2 + (1/2)^3 + (1/2)^4

we could just add them up, but I guess this question deals with the sum of a GS

a = 1
r = .5
n = 5
sum(5) = 1(.5^5 - 1)/(.5 - 1)
= (.03125 - 1)/(-.5) = 1.9375 or 31/16