You wish to test the following claim (Hₐ) at a significance level of α=0.01.
H₀:μ = 81.7
Hₐ:μ ≠ 81.7
​You believe the population is normally distributed and you know the standard deviation is σ=13.5. You obtain a sample mean of M=84.7 for a sample of size n=39. What is the test statistic for this sample?