What does a p-value of 0.05 mean?

A p-value of 0.05 means there's a 5% chance of observing your results (or more extreme) if the null hypothesis were true. It's commonly used as a threshold for statistical significance.

What's the difference between one-tailed and two-tailed tests?

One-tailed tests look for effects in a specific direction (greater than or less than). Two-tailed tests look for effects in either direction (different from). Two-tailed tests are more conservative and commonly used.

When should I use a z-test vs t-test?

Use z-test when you know the population standard deviation or have large samples (n>30). Use t-test when you don't know the population standard deviation and have smaller samples.

Can a p-value prove my hypothesis is correct?

No, p-values cannot prove hypotheses. They only indicate whether your data is consistent with the null hypothesis. A low p-value suggests the null hypothesis is unlikely, but doesn't prove your alternative hypothesis.

P-Value Calculator – Statistical Significance

Calculate p-values for statistical tests including z-tests, t-tests, and chi-square tests. Determine statistical significance and interpret results.

P-Value Calculator – Statistical Significance

Calculate p-values for statistical tests including z-tests, t-tests, and chi-square tests. Determine statistical significance and interpret results.

Test Type*

Type of statistical test

Test Statistic*

Calculated test statistic value

Degrees of Freedom

Degrees of freedom (for t-test and chi-square)

Test Type*

Direction of the statistical test

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Understanding P-Values

A p-value measures the probability of obtaining test results at least as extreme as the observed results, assuming the null hypothesis is true. It's a key component in hypothesis testing and determining statistical significance.

Interpreting P-Values

P-value interpretation guidelines:

p < 0.001: Very strong evidence against null hypothesis
p < 0.01: Strong evidence against null hypothesis
p < 0.05: Moderate evidence against null hypothesis (commonly used threshold)
p < 0.10: Weak evidence against null hypothesis
p ≥ 0.10: Little or no evidence against null hypothesis

How to Use This Calculator

Follow these simple steps to get accurate results:

Enter your test type
Enter your test statistic
Enter your degrees of freedom
Enter your test type
Click the "Calculate" button to see your results
Review the detailed breakdown and explanation

Why Use Our P-Value Calculator – Statistical Significance?

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Instant, accurate calculations with professional formulas
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Educational content to help you understand the results

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