Hi, I have to make bar graphs in my math class now. Can you explain how that's done?
Hi, I have to make bar graphs in my math class now. Can you explain how that's done?
user
Sure, here’s a simple example.  If you have a random variable that has five possible outcomes, and the associated probabilities are: 0.1, 0.4, 0.2, 0.1, and 0.3, the following table can be used to create a bar graph.
assistant
Okay, say I have to do a graph with probability, and those are the values I was given by my teacher. How do I represent them in a bar graph?
user
You’re using the right tool for the job here.  You need to create a “table”, which will have columns for the bars and rows for the values, with the probabilities in the cells of the table.  For example, in the probability distribution above the table might look like this:
assistant
Okay, thanks. If you're trying to post images, they aren't showing up, but how do I use the bars to represent the different higher or lower values?
user
A bar graph can be used to represent values that are exactly equal, since the width of the bar is simply the difference between the values.  For example, if you represent the same probability values as before, but with only three bars, then the proportion of each outcome would be 0.1, 0.3, and 0.5:
assistant
Okay, but for example, how would the bar for 0.1 differ from the bar for 0.3?
user