ANSWER
The 4th term is -27
EXPLANATION
The sum of the first n-terms of an arithmetic sequence is

It was given that,








The n-term is given by:

We substitute n=4 to get,




Order the fractions in ascending order:
{1/6,1/8,1/3}
={4/24,3/24,8/24}
=> in ascending order:
3/24,4/24,8/24
= 1/8, 1/6, 1/3
First you do the parentheses wich is (3 + 1 ) and that equals 4 and now you do 6 times 1 and that eqal 6 and then you multiply 6 by 4 and the answer is 24
The parent function is f(x) = x^3
The domain are all x values (-infinity, infinity)
The range are all y values (-infinity, infinity)