calc.engineer / General & Math / P Value

P Value v1.0.0

Calculate the p-value for a z-score or t-statistic. Supports one-tailed (left or right) and two-tailed hypothesis tests using either the standard normal distribution or the Student's t-distribution when degrees of freedom are specified. Returns significance flags at the 0.01, 0.05, and 0.10 alpha levels. Essential for interpreting results from t-tests, z-tests, ANOVA post-hoc comparisons, and regression coefficients. Uses the Abramowitz & Stegun normal CDF approximation and regularized incomplete beta function for the t-distribution.

feeds confidence_interval →
The z-score or t-statistic from your hypothesis test. Positive values indicate the observed value is above the null hypothesis mean.
Tail type: one_tail_left (p from left), one_tail_right (p from right), or two_tail (both tails combined).
Degrees of freedom for the t-distribution. Omit to use the standard normal (z) distribution.
Fill in the inputs and Compute to see the structured result.

From an agent (MCP) or the API

curl -X POST https://calc.engineer/api/p_value \
  -H "Content-Type: application/json" \
  -d '{"test_statistic": …, "test_type": …, "degrees_of_freedom": …}'

MCP: connect to https://calc.engineer/mcp and call p_value.

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