Chore(AI): Update accuracy to 78.9%

subjects/ai/kaggle-titanic/README.md

@@ -43,7 +43,7 @@ The way the Kaggle platform works is explained in the challenge overview page. I
 
 #### Scores
 
-In order to validate the project you will have to score at least **79% accuracy on the Leaderboard**:
+In order to validate the project you will have to score at least **78.9% accuracy on the Leaderboard**:
 
 - 78.9% accuracy is the minimum score to validate the project.
 

subjects/ai/kaggle-titanic/audit/README.md

@@ -43,7 +43,7 @@ project
 
 #### Final score
 
-###### Is the accuracy associated with the username in `username.txt` higher than 79%? The best submission score can be accessed from the user profile.
+###### Is the accuracy associated with the username in `username.txt` higher than 78.9%? The best submission score can be accessed from the user profile.
 
 #### Examples