Assumptions: a) Simple Random Sample
b) Normal Population or Large Sample
c) σ Unknown
Step 1: Set up null and alternative hypotheses.
H0: μ =
H1: μ ≠
Step 2: Input α (level of significance of hypothesis test).
α =
(Note: α = level of significance of hypothesis test
= probability of making Type I error.)
Step 3: Input x̅, n, s; and then calculate Test Statistic.
x̅ (sample mean) =
n (sample size) =
s = (sample standard deviation) =
Test Statistic =
x̅ - μ
/
s/√n
Step 4: Find Critical Values (-tα/2, tα/2)
Note: Since σ is unknown, t-distribution is used to find the critical values.
-tα/2 is the t-score corresponding to the left-tailed area.
tα/2 is the t-score corresponding to the right-tailed area.