Hi. I have this question I need some help.

Given a random sample of size $\displaystyle n$ from a normal population with known variance $\displaystyle \sigma^2$, show that the null hypothesis $\displaystyle H_0:\mu = \mu_0$ can be tested against the alternative $\displaystyle \mu\not=\mu_0$ using a one tailed criterion based on the chi-square distribution.

do I use this? $\displaystyle \chi^2 \frac{(n-1)s^2}{\sigma^2}$

I just don't know where to start on this problem...