Scattergraph Method

The following data was gathered for five production runs of ABC Company. As the scatter graph shows a weak correlation between the number of pages in a magazine and its cost, the answer to part (b) is not very reliable and should only be considered a rough estimate. Scatter graphs visually show the correlation between two variables. Here is a set of bivariate data showing the height and weight of ten students and the corresponding scatter graph.

  • This step requires that each data point be plotted on a graph.
  • A scatter plot is a chart type that is normally used to observe and visually display the relationship between variables.
  • Each dot represents a single tree; each point’s horizontal position indicates that tree’s diameter (in centimeters) and the vertical position indicates that tree’s height (in meters).
  • However, the heatmap can also be used in a similar fashion to show relationships between variables when one or both variables are not continuous and numeric.
  • Categorical scattergraphs are best for data that includes categorical variables, such as gender or location.
  • Before you can create a scattergraph, you need to clean and format your data appropriately.

To determine the variable cost per unit, all costs identified as variable are totaled and divided by the measure of activity (units produced is the measure of activity for Bikes Unlimited). Business managers use the scattergraph method when estimating costs to anticipate operating costs at different activity levels. Also known as a semi-fixed cost, this refers to a cost composed of a mixture of both fixed and variable components. Costs are fixed for a set level of production or consumption, and become variable after this production level is exceeded. If no production occurs, a fixed cost is often still incurred.

Step 4: Find variable cost per unit

The method derives its name from the overall image of the graph, which consists of many scattered dots. Ideally, the result of a scattergraph analysis is a formula with the total amount of fixed cost and the variable cost per unit of activity. A scattergraph uses a horizontal x-axis that represents a firm’s production activity and a vertical y-axis that represents its cost. Data are plotted as points on the graph, and a regression line that runs through the dots represents the best fit of the relationship between the variables.

Cost accountants will often throw out the high and low points for this reason and use the next highest and lowest points to perform this analysis. The scatter plot is a basic chart type that should be creatable by any visualization tool or solution. Computation of a basic linear trend line is also a fairly common option, as is coloring points according to levels of a third, categorical variable. Other options, like non-linear trend lines and encoding third-variable values by shape, however, are not as commonly seen. Even without these options, however, the scatter plot can be a valuable chart type to use when you need to investigate the relationship between numeric variables in your data.

The relationship between age and reaction time is likely to be non-linear. By transforming the variables, such as taking the logarithm or square root of the reaction time, you can create a better scattergraph that accurately represents the relationship. Scattergraphs are one of the most effective ways to visualize relationships between two variables. However, creating a scattergraph requires careful data preparation.

  • The shop manager decides to record the cost of each magazine and the number of pages it has.
  • Heatmaps can overcome this overplotting through their binning of values into boxes of counts.
  • Scattergraphs, also known as scatter plots, are a powerful tool in data visualization used to display the relationship between two variables.
  • For example, if we want to represent the correlation between the hours of study and the grades obtained by students, we can plot the data on the scattergraph.
  • However, creating a scattergraph that is visually appealing can be a challenge.
  • In this section, we will explore some tips and tricks that will help you create scattergraphs that not only display data accurately, but also have visual appeal.

A line of best fit is a straight line drawn through a scatter graph which shows correlation. It is referred to as an estimated line of best fit because it is drawn by hand following some guidelines. The scatter plot is one of many different chart types that can be used for visualizing data.


It is evident from this information that this company has very little in fixed costs and relatively high variable costs. This is indicative of a company that uses a high level of labor and materials (both variable costs) and a low level of machinery (typically a fixed cost through depreciation or lease costs). Once the data points are plotted as described in step 1, draw a line through the points touching one data point and extending to the y-axis. The goal here is to minimize the distance from the data points to the line (i.e., to make the line as close to the data points as possible).

Cost Function

Mastering the art of scattergraph method is an important skill for anyone who wants to analyze data effectively. Whether you are in the field of medicine, economics, or sports, scattergraphs are a powerful tool that can help you make better decisions and achieve better outcomes. Interpreting scattergraphs is an essential skill for anyone working with data, from analysts to business leaders.

Similar Accounting Post

However, you must remember that bivariate data has a subject and two variables are recorded for each subject. The number of points on the graph tells us the number of subjects. Here we will learn about scatter graphs, including how to plot scatter graphs, describe correlation, draw an estimated line of best fit and interpolate and extrapolate data. When the two variables in a scatter plot are geographical coordinates – latitude and longitude – we can overlay the points on a map to get a scatter map (aka dot map). This can be convenient when the geographic context is useful for drawing particular insights and can be combined with other third-variable encodings like point size and color. When a scatter plot is used to look at a predictive or correlational relationship between variables, it is common to add a trend line to the plot showing the mathematically best fit to the data.

In other words, a relationship between two variables does not indicate that one variable causes another. For example, you may find a positive correlation between temperature and the number of ice-creams sold. You can describe the relationship as the hotter the temperature, the greater the number of ice-creams sold. In the same way you cannot say that higher ice cream sales cause hotter temperatures.

Common scatter plot options

The total variable is calculated by subtracting fixed costs from the total mixed cost. It helps in estimating the variable and fixed components of a mixed cost by plotting past historical data points and then fitting a straight line (often done manually) through the scattered points. Scatter graph method is a graphical technique of separating fixed and variable components of mixed cost by plotting activity level along x-axis and corresponding total cost (i.e. mixed cost) along y-axis. A regression line is then drawn on the graph by visual inspection.

The estimated number of hours worked per week by a person aged 64 is 8 hours. As we want the temperature for 30 ice cream sales, we need to locate 30 on the vertical axis. We now draw a horizontal line from the line of best fit to the other axis. Draw a vertical/horizontal line from the point on the line of best fit to the other axis.

A semi-variable expense is more complicated to analyze since it is made up of both fixed and variable factors. A scatter plot (aka scatter chart, scatter graph) uses dots to represent values for two different numeric variables. The position of each dot on the horizontal and vertical axis indicates values for an individual data point. Scatter plots are used to observe relationships between variables.

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