What is Test Statistic?
A test statistic is a numerical value calculated from sample data used in hypothesis testing. It measures how far your sample statistic deviates from the null hypothesis. Calculation involves comparing sample means, proportions, or other parameters to population values, standardized by accounting for sample size and variability. This standardized value helps determine statistical significance by showing how extreme the results are relative to the assumed null hypothesis. It's crucial for making objective decisions in statistical analysis across various fields including science, economics, and social research.
Test Statistic Formula
The basic formula for z-test statistic is:
z = (X̄ - μ) / (σ/√n)
Where:
X̄ = Sample mean
μ = Population mean
σ = Standard deviation
n = Sample size