1.2 Misleading graphs

It’s summer, and you planned to put up a juice stand in front of your yard, now your problem is that you want to know how many people would prefer buying lemonade or orange juice and what time do they usually buy. So during the first day of your sales, you tried counting all the people who bought lemonade and counted all of those who bought orange juice and also placed the time interval when these were bought.

At the end of the day, you are looking at a stash of money, and a bunch of data that you would study to improve your sales. So how do you understand that data then?

By then, you would need to find a way to make sense out of all these. You would need the time interval when a certain glass was bought, and a bar graph to represent the number of lemonade and orange juice sold. But the problem is, you don’t have any idea to do it.

Thanks to this chapter, you would learn how to do that in no time. This chapter will initially tackle Interval. As mentioned earlier you would be using the time interval to know what time is the best for you to sell your fruit juices. Interval is the set of real numbers that lies between two sets of numbers. Say you have an hour interval, like 8:30 to 9:30, all of the minutes included in this hour would be a part of this interval.

Then we also mentioned making a graph, specifically a bar graph, but why did we choose this in the first place? Now in the first part of this chapter, you will be learning about the advantages and disadvantages of different kinds of graph.

There are many kinds of graph, namely, circle graphs, line graphs, pictographs, and bar graphs. You can make graphs in blank paper, but it’s a lot easier to make one with graph paper. There is also a free graphing tool over the internet to help you graph out your data and put it in a Word file.

Graphs show us trends a lot easier than just looking at a set of number. But it’s very important that we know how to make them properly as to not distort the data we have. In the second part of this chapter, we will learn all about misleading graphs so that you won’t make these mistakes.

In the last part of this chapter, we will be looking closely at how to critique a data representation. In that way, you can effectively turn your data into graphical representation. This would help you understand more about the numbers that you have for those fruit juices, and the best time interval to sell them.

The following are examples of line graph and bar graph:
Line Graph

Bar Graph

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Misleading graphs

Graphs are handy when it comes to representing data. However, they can be misleading if they are not done properly. In this section, we will learn how to identify the mistakes, and avoid them when we draw graphs.

Lessons

  • 1.
    The numbers of cars sold by 3 dealers were displayed in a bar graph.

  • 2.


  • 3.
    The following graph shows the marks that two students got for their final exam.

Teacher pug

Misleading graphs

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