Amount is a type of Magnitude. Margin is a type of Amount. 
Text can be used for Study. you are likely to find Text in/at/on Newspaper. you are likely to find Statement in/at/on Newspaper. Statement is a type of Message. 
Magnitude <--IsA-- Amount <--IsA-- Margin 
Study <--UsedFor-- Text --AtLocation--> Newspaper <--AtLocation-- Statement --IsA--> Message 