some exercises ' going to give you little assignment in this section if you open up fbo fejbo&yfsdjtfjqzoc filethere' some stuff you can play with want you to roll up your sleeves and actually try to do this in the filewe have some random -commerce data what this data represents is the total amount spent per transactionand againjust like with our previous exampleit' just normal distribution of data we can run thatand your homework is to go ahead and find the mean and median of this data using the numpy package pretty much the easiest assignment you could possibly imagine all the techniques you need are in the fbo fejbo pefjqzoc file that we used earlier the point here is not really to challenge youit' just to make you actually write some python code and convince yourself that you can actually get result and make something happen here sogo ahead and play with that if you want to play with it some morefeel free to play around with the data distribution here and see what effect you can have on the numbers try adding some outlierskind of like we did with the income data this is the way to learn this stuffmaster the basics and the advance stuff will follow have at ithave fun once your're readylet' move forward to our next conceptstandard deviation and variance standard deviation and variance let' talk about standard deviation and variance the concepts and terms you've probably heard beforebut let' go into little bit more depth about what they really mean and how you compute them it' measure of the spread of data distributionand that will make little bit more sense in few minutes standard deviation and variance are two fundamental quantities for data distribution that you'll see over and over again in this book solet' see what they areif you need refresher