docs: documentation and ci/cd and apply Black formatter.

Author: praisetompane

.github/workflows/statistics.yaml

@@ -7,12 +7,21 @@ on:
     branches: [ main ]
 
 jobs:
-  spell_check:
+  build:
     runs-on: ubuntu-latest
     steps:
-    - name: check out repo
+    - name: Check Repository
       uses: actions/checkout@v4
-    - name: spell check
+    - name: Spell Check
       uses: rojopolis/spellcheck-github-actions@0.45.0
-      with:                                        
+      with:       
+        task_name: English                                 
         output_file: spellcheck-output.txt
+    - name: Install Pipenv
+      run: python -m pip install pipenv
+    - name: Install Dependencies
+      run: pipenv sync --system -d
+    - name: Style Check
+      run: black --check .
+    - name: Run Tests
+      run: pytest

.spellcheck_exceptions_dictionary.txt

@@ -95,6 +95,7 @@ trinomial
 sentential
 
 # technology
+pytest
 ary
 forall
 forallx

0_elementary/0_central_tendency.txt

@@ -0,0 +1,64 @@
+def central tendency:
+    - formal: ???
+
+        - in words: ???
+
+    - plain english: ???
+
+    - intuition:
+        given:
+            6 plants with heights:
+                4, 3, 1, 6, 1, 7
+        then:
+            How tall are your plants, given as one number?        
+            Ans: average of the heights | typical number | middle number | center number | frequent number 
+                 i.e. The central tendency of the numbers.
+
+    - properties:
+        - common central tendency measures (KhanAcademy):
+            1. Arithmetic Mean = Sum of all numbers/Number of numbers. 
+                NB: Human constructed definition we've found useful(unlike the
+                circumference of circle, π, etc which exist in the mathematical universe)
+
+                (4 + 3 + 1 + 6 + 1 + 7)/6 = 22/6 = 3*4/6 = 3*2/3 NB: In mixed number form
+                
+                NB: Used frequently
+                Key: If the total quantity was distributed evenly in the dataset,
+                    the Mean is the quantity that each "position(i.e. index 0,1,2,...n)" would have  (KhanAcademy). 
+                    
+            2. Median = Middle number in the ordered(ascending) version of the dataset. 
+                algorithm:
+                    If odd number count, take middle number
+                    Else even number count, take Arithmetic Mean of the two middle numbers
+                    
+                
+                1, 1, 3, 4, 6 ,7
+                    ∴ Median = (3 + 4)/2 = 7/2 = 3*1/2
+
+                0, 7, 50, 10000, 100000
+                    ∴ Median = 50
+
+                NB: Useful when some large number might skew the Arithmetic Mean
+
+            3. Mode = Most frequent number in the dataset. 
+                algorithm:
+                    count occurrences of each number
+                    find number with highest occurrence count
+                        if no single number has the highest frequency, then
+                            the dataset has no mode
+
+                1, 1, 3, 4, 6, 7
+                    ∴ Mode = 1
+
+                1, 6, 3, 9, 8
+                    ∴ Mode = None
+
+    - examples: ???
+
+    - use cases: ???
+        
+    - proof: ???
+    
+References:
+    - KhanAcademy. https://www.khanacademy.org/math/cc-sixth-grade-math/cc-6th-data-statistics/mean-and-median/v/statistics-intro-mean-median-and-mode.
+    - KhanAcademy. https://www.khanacademy.org/math/cc-sixth-grade-math/cc-6th-data-statistics/mean-and-median/a/calculating-the-mean.

0_elementary/1_models.txt

@@ -6,10 +6,13 @@ name = "pypi"
 [packages]
 numpy = "*"
 matplotlib = "*"
+graphviz = "*"
 
 [dev-packages]
 pyspelling = "*"
 ipykernel = "*"
+pytest = "*"
+black = "*"
 
 [requires]
 python_version = "3.13"