Understanding how to visualize data onto graphs

With our assignment for homework 3/4 we have to get familiar with one of the data sets and R and then extend the analysis of the data by using R. To do this we have to understand how to look at data and then visualize it in graphs to help us better understand correlations. I found a few helpful videos on Khan Academy to help understand how we visualize data in graphs. This may seem too basic for some people in the class but it was helpful for me at the level I am at in my understanding of data analysis.

http://www.khanacademy.org/math/algebra/ck12-algebra-1/v/histograms

http://www.khanacademy.org/math/algebra/linear-equations-and-inequalitie/v/interpreting-linear-graphs