47.44 is the answer to this question
Answer:

Step-by-step explanation:
We have a geometric sequence with:
,
, and 
Where
Sn is the sum of the sequence
r is the common ratio
is the first term in the sequence
n is the number of terms in the sequence
The formula to calculate the sum of a finite geometric sequence is:

Then:

Now we solve for 


the answer..... I got was 18