Posted by **Bob** on Monday, June 3, 2013 at 9:58pm.

sorry for before it is my first time using this website and this is the real question

in a geometric series t1=23,t3=92 and the sum of all of the terms of the series is 62813. How many terms are in the series?

- math -
**Reiny**, Monday, June 3, 2013 at 10:20pm
t1 = 23 ---> a = 23

t3 = 92 --->ar^2 = 92

divide them

r^2 = 4

r = ± 2

sum(n) = a(r^n - 1)/(r-1) = 62813

If r = 2

23( 2^n - 1)/(2-1) = 62813

2^n - 1 = 2731

2^n = 2732

but ....

n has to be a whole number, since it stands for the number of terms

2732 is NOT a power of 2,

so even though you typed it again with a correction , the question is still flawed.

## Answer This Question

## Related Questions

- Algebra - Use the geometric sequence of numbers 1, 1/3, 1/9, 1/27… to find the ...
- Math....Please help I have a deadline for tonight! - Use the geometric sequence ...
- CALC II - Determine the convergence of the following series using the nth-...
- math help - the sum of the first two terms in a geometric series is 12. the sum...
- Math - The first two terms in a geometric series is 12. The sum of the first ...
- math studies - An arithmetic series has a first term of -4 and a common ...
- Math - If S1 = 0.7 and S2 = 2.1 in a geometric series, determine the sum of the ...
- math help!! - the first term in a geometric series is 4 and the sum of the first...
- Math. - The first term of a geometric series is 4 and the sum of the first three...
- math - in a geometric series t1=23,t3=92 and the sum of all of the terms of the ...

More Related Questions