What is the value of the fourth term in a geometric sequence for which #a_1# = 15 and r = 1/3?

1 Answer
Jul 13, 2016

Answer:

#a_4=5/9#

Explanation:

The standard geometric sequence is.

#color(red)(|bar(ul(color(white)(a/a)color(black)(a,ar,ar^2,ar^3,......)color(white)(a/a)|)))#
where the first term is represented by a, and each term of the sequence is obtained by multiplying the previous term by r, the common ratio.
The nth term is #color(red)(|bar(ul(color(white)(a/a)color(black)(a_n=ar^(n-1))color(white)(a/a)|)))#

Here a = #a_1=15" and " r=1/3#

#rArra_4=15xx(1/3)^3=15xx1/27=5/9#