# Newbie... I need help.

#### dreamer

##### New Member
I don't have anyone to ask at the moment, and I was trying to get some answers on the Net, and found this forum.
I am trying to understand percentiles and deciles. There's not much about it in my book, so I asked some of my friends, but they seem to be uncertain about this just as much as I am.
Anyway... my question is this:
in my book it's stated that the 1st decile starts with the 1st percentile, and the 2nd one with 20th percentile and so on.

What I don't get is, if the median is in the 5th decile, why does the book say that the 2nd decile starts with the 20th percentile, because according to that, 5th decile starts with the 40th percentile, and the 6th decile starts with the 50th. but apparenty the median is not in the 6th decile, but in the fifth (??)

I would really appreciate the explanation