1 Proportion Z-Test Formula:
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The 1 Proportion Z-Test is a statistical test used to determine whether a sample proportion differs significantly from a hypothesized population proportion. It's commonly used in hypothesis testing for proportions.
The calculator uses the 1 Proportion Z-Test formula:
Where:
Explanation: The formula calculates how many standard deviations the observed sample proportion is from the hypothesized population proportion.
Details: The z-score helps determine whether the difference between the sample and population proportions is statistically significant, which is crucial for hypothesis testing in research and data analysis.
Tips: Enter the sample proportion (between 0 and 1), hypothesized proportion (between 0 and 1), and sample size (positive integer). All values must be valid.
Q1: When should I use a 1 Proportion Z-Test?
A: Use it when you want to test whether a single sample proportion differs from a known or hypothesized population proportion.
Q2: What are typical z-score thresholds?
A: Common critical values are ±1.96 for 95% confidence (α=0.05) and ±2.576 for 99% confidence (α=0.01).
Q3: What sample size is needed?
A: The test works best when np₀ and n(1-p₀) are both ≥10. Larger samples give more reliable results.
Q4: How does this differ from t-test?
A: Z-tests are for proportions with known variance, while t-tests are typically for means with unknown variance.
Q5: Can I use this for small samples?
A: For small samples (n < 30), consider using exact binomial tests instead as z-tests may not be accurate.