To find the common ratio of the sequence, divide each of the elements of the sequence by the element that precedes it:
Since the quotient is always -3, then the common ratio is equal to -3.
To find the fifth term of the sequence, multiply the fourth term, which is -81, times -3:
Once that we know the first five terms of the sequence, add them to find their sum:
Therefore:
The common ratio of the sequence is -3.
The sum of the first five terms of the sequence is 183.