general

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.

post/api/p_value

Request

  • Base URL: https://calc.engineer
  • URL: https://calc.engineer/api/p_value
  • Auth: none declared

Request body

test_statisticnumber required

The z-score or t-statistic from your hypothesis test. Positive values indicate the observed value is above the null hypothesis mean.

test_type'one_tail_left' | 'one_tail_right' | 'two_tail'

Tail type: one_tail_left (p from left), one_tail_right (p from right), or two_tail (both tails combined).

degrees_of_freedomnumber

Degrees of freedom for the t-distribution. Omit to use the standard normal (z) distribution.

Response

Computed result for p_value

toolstring required
versionstring required
computed_atstring date-time required

Changes

No recorded changes to this operation across all 1 revision of this API.