Answer
$$0.2$$
Work Step by Step
The Alternating Series Test states:
Consider a series $\Sigma a_n$ such that $p_n=(-1)^n q_n$; $q_n \geq 0$ for all $n$
If the following conditions are satisfied then the series converges:
a) $\lim\limits_{n \to \infty} q_n=0$;
b) $q_n$ is a decreasing sequence.
Consider $S_n=a_1-a_2+......+(-1)^{n+1}a_n$
and $|S-S_n|=\leq |a_{n+1}|$
$\implies |\space Error |=|S-S_4| \leq |a_{4+1}|=|a_5| \\ =|(-1)^6 \times \dfrac{1}{5} | \\=0.2$