Update QA

Author: MehrdadShirvani

content/01-Topics/00-Math-Foundation/06-QA.md

@@ -161,7 +161,7 @@ This gives you an **approximate bias**, even if θ is unknown.
 
 
 
-## Question: Comparing `X` and `X̄` as Estimators of the Mean 
+## Q: Comparing `X` and `X̄` as Estimators of the Mean 
 Answer: 
 ### Goal
 
@@ -224,7 +224,7 @@ An estimator is more **efficient** if it has **lower variance**, assuming the sa
 - But $(\bar{X})$ is far more **reliable** due to lower variance
 - ➤ **Use $(\bar{X})$** when you have more than one sample
 
-## Question: **Why is $( \mathbb{E}[X] = \mu)$** if (X) is just a **single observation**?  
+## Q: **Why is $( \mathbb{E}[X] = \mu)$** if (X) is just a **single observation**?  
 
 ### The Key Distinction: **Random Variable** vs **Realized Value**
 When we write: