Question

if the first term of an arithmetic sequence is 9 and the fifth term is 25, what is the 3rd term?

select one:
a. 17
b. 26
c. 21
d. 7

Explanation:

Step1: Recall arithmetic sequence property

In an arithmetic sequence, the middle term of three consecutive terms is the average of the other two. The 3rd term is the midpoint of the 1st and 5th terms.

Step2: Calculate the 3rd term

$\text{3rd term} = \frac{\text{1st term} + \text{5th term}}{2} = \frac{9 + 25}{2}$

Step3: Simplify the expression

$\frac{34}{2} = 17$

Answer:

A. 17