Answer
$13$
Work Step by Step
The missing term of the given arithmetic sequence can be found by solving the arithmetic mean of $4$ and $22$.
The arithmetic mean can be found by adding two numbers and dividing the sum by$2$. Thus, the artihmetic mean of $4$ and $22$ is:
$$=\dfrac{4+22}{2}\\\\
=\dfrac{26}{2}\\\\
=13$$
