Given the following hypotheses:
H0: μ = 400 H1: μ ≠ 400
A random sample of 12 observations is selected from a normal population. The sample mean was 407 and the sample standard deviation was 6.
Using the 0.01 significance level:
(a) State the decision rule. (Negative amount should be indicated by a minus sign. Round your answers to 3 decimal places.)
(b) Compute the value of the test statistic. (Round your answer to 3 decimal places.)
(c) What is your decision regarding the null hypothesis?