A scatter plot refers to that type of graph which you can use to represent the correlation between two different variables. How to make a scatter plot, when you have two variables. You can easily make a scatter plot after reading this article.
Let us take an example, it’s generally believed that the amount of time spent preparing for an exam will have a direct effect on how well a student will perform in that exam. To justify this theory, you can gather information from several students. The information would be of the number of hours they spend studying and their final test scores. You can then transfer the information into a scatter plot.
You can create many different types of scatter plots in Microsoft Excel 2007. We will however, focused on the most common variety. This is the scatter plot with only markers, in these instructions. You can easily adapt these steps and you can create any other types of scatter plots in Excel.
A scatter plot relates two paired sets of data. It is very useful for finding the correlation between the two data sets.
How to make a scatter plot:
First of all, draw a grid. Draw a horizontal line i.e. X Axis. Now, draw a vertical line i.e. Y Axis. Y axis will intersect the center of the horizontal line. You can do this effectively on the graph paper as you can exactly plot each point of data rather than guessing the approximate location. If all the data points are positive numbers, you do not require the whole grid. In such a scenario, you can draw an L shape facing right. The bottom line of the L is the X axis, and the vertical boundary is the Y axis.
Label each axis:
The scale of the plot depends solely on the type of data you deal with. For instance, the scale may be from 1 to 10 with the labels at every whole number. It can also go from 1 to 100 with the labels occurring at every 10 numbers. It may be from 0 to 1, with labels happening at every 0.1.
Plot the data points:
The first column of data relates the orientation along the X axis. The second column relates the data points’ orientation along the Y axis. For instance, when the point is (3, 5), you need to plot it 3 units to the right of the origin, and five units up. You have to represent each point by a small dot or x-mark. If there are two sets of data not in the form of (3, 5), then the horizontal axis has to be the independent variable. This is the one you think has caused the other. The vertical axis is the dependent variable. This is the one which is caused by the other set of data.
View the results:
If the results is closely grouped just like a line or parabola (U or V shape), then you can say that there is a strong correlation between the two sets of data. When they do not seem to be related, the correlation between the two sets of data is weak or there is no correlation. When there is a strong correlation and there is a sharp slope, then a change in the first variable results in the change in the second variable. If the slope is less or no slope (horizontal), a relatively large change in the first variable will only change the second variable a little.
Algebra makes the best use of the scatter diagram. There are also many real time applications where you can use it. For example, note the readings for “lung capacity” (first variable) and how much time that person could hold his breath (second variable). The researcher can now plot the data in a scatter plot by taking “lung capacity” in the X-axis and “time holding breath” in the Y-axis.
It requires a proper care to locate the data points in a scatter plot. You need to understand to locate the data points in the graph effectively. You also need to locate the points according to the scale specified earlier. Now, you are ready to how to make a scatter plot. Choose the horizontal axis and vertical axis wisely and interpret the results eventually.