How Is P Value Calculated

P value, or probability value, is a crucial statistical measure used to determine the significance of observed data in a hypothesis test. It helps researchers assess whether the results are statistically significant or occurred by chance.

Formula: The P value is calculated using the formula: (observed – expected) / sqrt(expected).

How to Use:

  1. Enter the observed and expected values in the respective input fields.
  2. Click the “Calculate” button to obtain the P value.
  3. The result will be displayed in the designated field.

Example: Suppose you have an observed value of 25 and an expected value of 20. Enter these values, click “Calculate,” and the P value will be presented.


  1. Q: What is a P value? A: The P value is a statistical measure indicating the probability of obtaining results as extreme as the observed data, assuming the null hypothesis is true.
  2. Q: Why is the P value important? A: It helps researchers assess the significance of their findings and make informed decisions about the null hypothesis.
  3. Q: What does a low P value mean? A: A low P value (typically ≤ 0.05) suggests that the observed results are unlikely to have occurred by chance, leading to the rejection of the null hypothesis.
  4. Q: Can the P value be negative? A: Yes, the P value can be negative, indicating a deviation from the expected results.
  5. Q: What is the significance level? A: The significance level (usually set at 0.05) determines the threshold for considering results statistically significant.

Conclusion: The P value is a powerful tool in statistical analysis, aiding researchers in drawing meaningful conclusions from their data. Our P value calculator simplifies the computation process, making it accessible to everyone engaged in hypothesis testing.

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