Answer:
The 27th term is 73.5.
Step-by-step explanation:
We want to find the 27th term of the arithmetic sequence:
15, 17.25, 19.5, 21.75, ...
We can write a direct formula. Recall that the direct formula for an arithmetic sequence is given by:
[tex]x_n=a+d(n-1)[/tex]
Where a is the initial term and d is the common difference.
From the sequence, we can see that our initial term a is 15.
To find the common difference, subtract a term and its previous term. Thus, the common difference will be:
[tex]d=17.25 - 15 = 2.25[/tex]
Thus, our direct formula is:
[tex]x_n=15+2.25(n-1)[/tex]
To find the 27th term, let n = 27. Substitute and evaluate:
[tex]\displaystyle \begin{aligned} x_{27} &=15+2.25((27)-1) \\ &= 15+2.25(26) \\&= 15+58.5 \\ &= 73.5\end{aligned}[/tex]
Thus, the 27th term is 73.5.
