The sum of the infinite geometric series?

Question

3/2 + 9/16 + 27/128 + 81/1024... is
a. 1.60
B. 2.35
c. 2.40
D. 2.45
E. 2.50

Basically, I justt need the equation...

Answer 1

S=t1/(1-r)

r must be 3/8 because 3/8 is multiplied by t each time

S=(3/2)/(1-(3/8))

S=2.4

I hope that this helps.

Answer 2

The equation for the sum of a geometric series is a/(1 - r), where

a: the first term of the series...and

r: the ratio (number) that the term is multiplied by to obtain the next term.

In this case, a = 3/2, and r = 3/8.

The sum is then...
(3/2)/(1 - 3/8)

= (3/2) / (5/8)

= (3/2) * (8/5)

= 24/10

= 12/5

= 2.40, so C

Answer 3

For an infinite geometric series, the formula is

S = a1/(1 - r)

Where a1 = the first term
r = the ratio.

In this case, r = 3/8 and a1 = 3/2. Therefore

S = (3/2) / (1 - 3/8)
S = (3/2) / (5/8) = (3/2) * (8/5) = 12/5.
Convert 12/5 to decimal, and you get 24/10, or 2.4.

Answer 4

Sum =a/(1-r), where r is the common multiplier and a is the first term in the series.

The common multiplier in this case is r = 3/8 and a = 3/2.

So go get the sum.

Answer 5

OK here's the equation for the infinite geometric series when the absolute value of R, | R | , < 1 :

S = a1 (A sub 1) / 1 - R


Good luck

Answer 6

S= a / (1-r)

a is the first term and r is the rate at which it increases so for this a would be 3/2 r would be .375
you plug those in the formula and you get 2.4 which is c

Answer 7

The formulation for the sum of an unlimited geometric series is A1 / (a million-r) as long as |r|