To solve this hypothesis testing problem, we need to calculate the test statistic for the given data. The hypothesis we have is a one-tailed test:
H0: μ≥16 (null hypothesis)
H1: μ<16 (alternative hypothesis)
Given data:
Sample size (n) = 36
Sample mean (x̄) = 15.4
Population standard deviation (σ) = 3
Population mean under H0 (μ) = 16
The formula for the z-test statistic is:
z = (x̄ − μ) / (σ/√n)
Substituting the given values into the formula:
z = (15.4 − 16) / (3/√36)
z = (−0.6) / (3/6)
z = (−0.6) / 0.5
z = −1.2
Thus, the calculated test statistic is −1.2, which matches the correct answer from the provided options.