What is the importance of scaling a bar graph?

Answer 1

scaling a bar graph can be used for two reasons, to jump past a large group of numbers unused (say the bar graph goes from 1-1000 but none of the data starts below 500)

Scaling can be important to emphasize a difference in numbers too, suppose item a is at 700, item b is at 850, and item c is at 1000. if your bar graph jumps from 1 to 500 and then goes up in increments of 100, it can make 700 look like its far less than 850 or 1000. this is usually a business tactic done to impress board members when presenting lackluster numbers.