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 # Course Logbook
 
-_A record of notes, reflections, and completed activities throughout the course._
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+_A record of notes, reflections, and completed activities throughout the course._
+
+## Mission 3: Use of Jupyter and notebook
+
+**Date:** June 17, 2025  
+**Duration:** Approximately 2 hours  
+**Directory:** `mooc-rr/module2/exo1`, `mooc-rr/module2/exo2`, `mooc-rr/module2/exo3`  
+**Tools used:** Jupyter Notebook, GitLab, Matplotlib, NumPy
+
+### What I did
+
+- Reproduced a PDF file in order to use some approaches to evaluate the value of pi.
+- Entered some daily data manually for analysis purposes.
+- Computed basic statistics: mean, standard deviation, minimum, maximum, and median.
+- Produced two visualizations: a sequence plot and a histogram.
+
+### What I learned
+
+- Analyzing and visualizing simple data using Python tools.
+- Formatting plots clearly in a computational notebook.
+- Pushing changes to GitLab during the task.
+- Resolving Git conflicts involving Jupyter notebooks.
+
+### Difficulties encountered
+
+At the beginning of the task, I encountered a Git error while trying to push my notebook to GitLab. The error stated that my local branch and the remote branch had diverged, with conflicting changes in the file `toy_notebook_en.ipynb`. Since I had not made any meaningful edits locally, I chose to discard my local version and keep the one on GitLab.
+
+### Notes
+
+Once the Git issue was resolved, I was able to finish the task without further problems.
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