Okay, so I have to construct a frequency distribution. My highest value is 25.3 and my lowest is 20.5. I have no idea what number of classes I want to pick and when I keep doing this it's not coming out right.

For example I did this : 25.3- 20.5/8 = .6

And this is what I got :

20.5- 21

21.5- 21.6

21.7- 22.2

22.3- 22.8

22.9- 23.4

23.5- 24

24.1- 24.6

24.7- 25.2

But 25.3 isn't included?! What did I do wrong? Please help?