# Alg 2

The first term of a geometric sequence is 25, and the fourth term is 1\5.

(a) Find the common ratio r.
r =

Find the fifth term.
a5 =

(b) Find the partial sum of the first eight terms.
S8 =

1. 👍 0
2. 👎 0
3. 👁 306
1. r^3 = (1/5)/25 = 1/125
so, r = 1/5

An = 5*(1/5)^(n-1) = 125/5^n

S8 = 25(1 - (1/5)^8)/(1 - 1/5) = 97656/3125

1. 👍 1
2. 👎 0
posted by Steve

## Similar Questions

1. ### Math

3,5,-5... The first term in the sequence of #'s shown above is 3. Each even # term is 2 more than the previous term and each odd # term, after the first, is -1 times the previous term. For example, the second term is 3+2, and the

asked by Mack on May 20, 2007
2. ### algebra1

Which of the following functions represents a geometric sequence? Why? Answer Choices The function f(x)=x7 represents a geometric sequence because each term is raised to the seventh power to make it greater. The function f(x)=7x

asked by miyah on October 9, 2017
3. ### math

The third term of a geometric progressiom is nine times the first term.if the second term is one-twenty fourth the fifth term.find the fourth term.ar^2=9a. r=sqr of 9 r=3.pls teach me how to get the first term and i can get the

asked by james on November 27, 2014
4. ### Algebra

I am so lost on these problems. Write a geometric sequence that starts with 3 and has a common ratio of 5. What is the 23rd term in the sequence. Write an arithmetic sequence that has a common difference of 4 and the eighth term

asked by Randy on June 17, 2016
5. ### maths

given 1,0.5,4,o.25,7,0.125,10 assume this pattern continues consistently 1.write down the 33th term in this sequence 2.determine the sum of the first 24 terms in this sequence.give the answer to five decimal place 2.1.in a

asked by memory on February 15, 2015
6. ### Math

1. The fourth and seventh terms of a geometric sequence are 6 and 384, respectively. What is the common ratio and the sixth term of the sequence? 2. The fifth and eight terms of a geometric sequence of real numbers are 7! and 8!

asked by Penny on March 13, 2015
7. ### maths

Given that the sum of the first four terms of a geometric sequence is 10 and the fourth term is half the third term . find the common ratio and the first term

asked by martin np on May 18, 2016
8. ### Algebra

Find the fifth term of a geometric sequence whose fourth term is 32/27 and whose seventh term is 256/729.

asked by Allyssa on March 18, 2015
9. ### Sj

Mathematics......Under number patterns-Geometric series If a question goes.determine the expression for the nth term of the following sequence if the a) 4th term is 24 and the 7th term is 192 in a geometric sequence.what formula

asked by Mahlogonolo on July 16, 2015
10. ### math

Find the fifth term of a geometric sequence whose fourth term is 8/9 and whose seventh term is 64/243.

asked by Alexis on March 16, 2015
11. ### Math

In a geometric sequence, the fourth term is -4, and the eighth term is -324. What is the tenth term?

asked by Ally on December 18, 2012

More Similar Questions