Answer
$39$
Work Step by Step
The missing term of the given arithmetic sequence can be found by solving the arithmetic mean of $25$ and $53$.
The arithmetic mean can be found by adding two numbers and dividing the sum by$2$. Thus, the arithmetic mean of $25$ and $53$ is:
$$=\dfrac{25+53}{2}\\\\
=\dfrac{78}{2}\\\\
=39$$
