Initial Data Analysis:
http://dataworldblog.blogspot.com.es/2017/06/initial-data-analysis_46.html
http://dataworldblog.blogspot.com.es/2017/06/initial-data-analysis-handling-missing.html
Least Squares Method:
http://dataworldblog.blogspot.com.es/2017/06/least-squares-method.html
Simple Linear Model:
http://dataworldblog.blogspot.com.es/2017/06/simple-linear-model.html