Question

Please help. For the sequence an=3(1/2)^(n-1), S1=3 and S2=4.5. How would you find S3, S4, S5, S6, and S7? (Carry out as many decimal places as calculator will allow.)

Answer 1

what type of sequence is this?

Answer 2

Geometric

Answer 3

I'm pretty sure :/

Answer 4

ok

Answer 5

i wud help....but im not gud @ math. :( sowee. but can u go on twiddla again? http://www.twiddla.com/580173

Answer 6

S3=5.25
S4=5.625
S5=5.8125
S6=5.90625
S7=5.953

Answer 7

Wow Sayan! How'd you figure that out?

Answer 8

a1=3
r=0.5
\[Sn=a1(1-r^n)/(1-r)\]

Answer 9

Thanks!

Answer 10

Welcome

Answer 11

Wait! How would you get S20? What value would it turn out to be?

Answer 12

5.999999