Update difference_test_documentation.rst

researchpy · May 11, 2021 · 100457d · 100457d
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commit 100457d
Showing 1 changed file with 3 additions and 3 deletions.
diff --git a/source/difference_test_documentation.rst b/source/difference_test_documentation.rst
@@ -162,12 +162,12 @@ to calculate Glass's :math:`\Delta`:
 
 Point-Biserial correlation coefficient r (between or within subjects design)
 """"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
-Rosenthal :cite:`rosenthal1991` provided the following formula to calculate
-the Pearson correlation coefficient r using the t-value and degrees of freedom:
+Tthe following formula to calculate
+the Point-Biserial correlation coefficient r using the t-value and degrees of freedom:
 
 .. math::
 
-  r = \sqrt{\frac{t}{t^2 + df}}
+  r = \frac{t}{\sqrt{t^2 + df}}
 
 The following formula is used to calculate the Point-Biserial
 correlation coefficient r using the W-value and N. This formula