Test cereal mass and invert a two-sided rejection

The mass, $x$ kg, of the contents of each packet in a random sample of 80 cereal packets is measured, with $\sum x=79.53$ and $\sum x^2=100.4621$.

(i) Test, at the 4% level of significance, whether the population mean mass of the contents is less than 1.10 kg.

(ii) In another test using the same data at 4%, $H_0$ states that the population mean is $\mu_0$ kg and $H_1$ states that it is not $\mu_0$ kg. Given that $H_0$ is rejected in favour of $H_1$, find the set of possible values of $\mu_0$.