A data shows ‘amount spent on items’ like: House rent , food , education etc.If you have to draw a horizontal bar graph then where will you put ‘amount spent on items’ on ‘vertical line’ or ‘horizontal line’?
Generally data are represented on the system of XY axis also known as cartesian axis.
The vertical line or Y- axis used to represent the frequency of data (i.e. number of entities) whereas horizontal line or X -axis used to represent class or type of data.
Thus, in Y -axis is used to represent the amount spent on items.