Limit in probability for Pareto sample

Let $\{X_n\}_{n\ge 1}$ be a sequence of independent and identically distributed random variables having the common probability density function $$f(x)=\begin{cases} \frac{2}{x^3}, & x\ge 1 \ 0, & \text{otherwise.} \end{cases}$$ If $\lim_{n\to\infty} P\left(\left|\frac{1}{n}\sum_{i=1}^n X_i - \theta\right| < \epsilon\right) = 1$ for all $\epsilon > 0$, then $\theta$ equals