I have done the lessons in predictive grouping which is in interactive lessons>>predictive grouping but it says am 75% complete only showing that i haven't completed one lesson called principal component analysis i clicked on this lesson "principal component analysis" and checked only to see that i had done it and also did its quiz which i scored 3/3 , i also restarted the lesson again and passed the quiz again with a 3/3 but still it says i haven't completed this lesson, why? what could be the solution to this issue?
