Geometric Sequence find the 23rd term.

[mathdad]

A geometric sequence has an initial value of 25 and a common ratio of 1.8. Write a function to represent this sequence . Find the 23rd term.

My Effort:

The needed function is

a_n = a_1•r^(n-1), n is the 23rd term, r is the common ratio and a_1 is the initial value.

a_23 = 25•(1.8)^(23 - 1)

Is this correct?

 

[skeeter]

yes

 

[mathdad]

a_23 = 25 * 1.8(23-1)

a_23 = 25 * (1.8)^(22)

a_23 = 10326071.3

Correct?

 

[HOI]

To one decimal place, yes. Do you have a reason for choosing to write the answer to one decimal place?