# What is a possible value for the missing term of the geometric sequence 1250,__,50,..?

##### 1 Answer

Jan 4, 2017

#### Explanation:

The general term of a geometric sequence has the form:

#a_n = a*r^(n-1)#

where

In our example:

#a_1 = 1250" "# and#" "a_3 = 50#

So:

#r^2 = (ar^2)/(ar^0) = a_3/a_1 = 50/1250 = 1/25 = 1/5^2#

Hence:

#r = +-1/5#

Then:

#a_2 = a*r^(2-1) = 1250*(+-1/5) = +-250#