Tino conducted a survey of all the eighth graders in his school for his math project.He asked each student how much he or she spent on school supplies at the beginning of the year (rounded to the nearest dollar) he also caculated the average amount spent and found it to be $15.50 unfortunately,it rained on the day he brought the graph to turn it in,and the last bar got smudged.What is the height of the smudged are?
Click this link and scroll to the bottom to find the graph http://edweb.tusd1.org/gververelli/Algebra%20Stuff/POTW/POW09.htm

Question

Tino conducted a survey of all the eighth graders in his school for his math project.He asked each student how much he or she spent on school supplies at the beginning of the year (rounded to the nearest dollar) he also caculated the average amount spent and found it to be $15.50 unfortunately,it rained on the day he brought the graph to turn it in,and the last bar got smudged.What is the height of the smudged are? 
Click this link and scroll to the bottom to find the graph http://edweb.tusd1.org/gververelli/Algebra%20Stuff/POTW/POW09.htm