Power of an LRT at the observed mean

Let a random sample of size 4 from a normal population with unknown mean $\mu$ and variance 1 yield the sample mean of 0.16. Let $\Phi(\cdot)$ be the cumulative distribution function of the standard normal random variable. It is given that $\Phi(2.28) = 0.989$, $\Phi(1.96) = 0.975$, $\Phi(1.64) = 0.95$. If the likelihood ratio test of size 0.05 is used to test $H_0: \mu = 0$ against $H_1: \mu \ne 0$, then the power of the test at the sample mean equals ____________ (rounded off to three decimal places).