Calculate P-Value for Z-Test by Hand
Introduction & Importance
Calculating the p-value for a Z-test by hand is a crucial skill in statistics. It helps you determine the significance of your results and make informed decisions…
How to Use This Calculator
- Enter your Z-score.
- Select the number of tails (one or two).
- Click ‘Calculate’.
Formula & Methodology
The p-value for a Z-test is calculated using the Z-score and the number of tails. The formula is…
Real-World Examples
Example 1
Suppose you’ve calculated a Z-score of 1.85 with two tails. To find the p-value…
Data & Statistics
| Z-Score | P-Value |
|---|---|
| 1.645 | 0.05 |
| 1.96 | 0.025 |
Expert Tips
- Always round your Z-score to two decimal places.
- Remember, a small p-value indicates strong evidence against the null hypothesis.
Interactive FAQ
What does a p-value of 0.05 mean?
A p-value of 0.05 means there’s a 5% chance of observing the results by chance if the null hypothesis is true.
How do I interpret the p-value?
If the p-value is less than your chosen significance level (usually 0.05), you reject the null hypothesis and conclude that there’s a significant effect.
Office for National Statistics – Government statistics
Centers for Disease Control and Prevention – Public health information