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1 Sample Proportion Test Calculator

1 Sample Proportion Test Formula:

\[ z = \frac{p - p_0}{\sqrt{\frac{p_0 (1 - p_0)}{n}}} \]

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1. What is the 1 Sample Proportion Test?

The 1 Sample Proportion Test is a statistical hypothesis test used to determine whether a sample proportion differs significantly from a hypothesized population proportion. It calculates a z-score to assess the statistical significance of the observed difference.

2. How Does the Calculator Work?

The calculator uses the 1 sample proportion test formula:

\[ z = \frac{p - p_0}{\sqrt{\frac{p_0 (1 - p_0)}{n}}} \]

Where:

Explanation: The formula calculates how many standard errors the sample proportion is away from the hypothesized proportion, providing a measure of statistical significance.

3. Importance of Z-Score Calculation

Details: The z-score helps determine whether the observed sample proportion is statistically significantly different from the hypothesized proportion, which is crucial for hypothesis testing in various research and quality control applications.

4. Using the Calculator

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 for accurate calculation.

5. Frequently Asked Questions (FAQ)

Q1: What does the z-score represent?
A: The z-score represents how many standard errors the sample proportion is away from the hypothesized proportion. Larger absolute values indicate stronger evidence against the null hypothesis.

Q2: When is this test appropriate?
A: This test is appropriate when you have a large sample size (n > 30) and want to test if a sample proportion differs from a known or hypothesized population proportion.

Q3: How do I interpret the z-score?
A: Typically, |z| > 1.96 suggests statistical significance at the 0.05 level, and |z| > 2.58 suggests significance at the 0.01 level (for a two-tailed test).

Q4: What are the assumptions of this test?
A: The test assumes random sampling, independence of observations, and that np₀ and n(1-p₀) are both greater than 5 to ensure normal approximation.

Q5: Can this test be used for small samples?
A: For small samples, the exact binomial test is more appropriate as the normal approximation may not hold well.

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