Percentile gives you an idea of where a value lies in the dataset (i.e., its position/rank in the dataset). It tells you the relative position of a data point in the whole dataset. For example, if I have the scores of 100 students and I tell you that the 90th percentile score is 92, it means that if anyone scores 92, then their score would be above 90% of the students. This is a preferred method as it’s more meaningful than just giving the score. For example, if I tell you that your score is 90, it doesn’t tell you where you stand relative to the others. But if I tell you that your score’s percentile is 90th, you immediately know that you have done better than 90% of the people who took the exam. Install the ToolPak To install the Analysis-ToolPak add-in select (Tools > Add-ins) , select "Analysis-ToolPak" and press OK. Troubleshooting MS URL