If the null hypothesis is true the sample mean should be in a confidence interval centered at μ
The random variable X has a normal distribution with mean μ and a standard deviation of 2.8.
A random sample of 36 observations is taken and the sample mean x ̅ is calculated in order to test the null hypothesis μ=16 against the alternative hypothesis μ≠16 using a 10% level of significance.
Find the critical region.