Home >> Science & Nature >> Science

How to Make Histograms With Classes

A graph is a visual way to represent data, and can aid in finding trends in complex data sets. There are many different types of graphs and these include scatter graphs, line graphs, and pie charts. A histogram is a graph in which frequency is plotted against each data class -- such as age. Histograms are typically used where numerical categories (classes) need to be quantified and are used frequently in the social sciences. Making a histogram is straightforward once data has been categorized into classes.

Things You'll Need

Graph paper

Instructions

- 1
  Write down the classes that will be used in the histogram. For example, if the age of 100 university student has been obtained, the data can be classed into a number categories; 0 to 20, 21 to 40, 41 to 60, and 61 to 80.
- 2
  Draw a frequency table to indicate the number of people in each class. Following the example, the frequency table would take the form:
  Frequency=
  Age=0 to 20 Frequency= 0
  Age=21 to 40 Frequency= 87
  Age=41 to 60 Frequency= 9
  Age=61 to 80 Frequency= 4
- 3
  Draw the x and y axes of the histogram on the graph paper. Place divisions along the x-axis and label each division with a class. Following the example, the classes along the x-axis would be "Age 0-20," "Age 21-40," etc. Place a scale along the y-axis in such a way that all data classes can be plotted on the histogram. Following the example, the maximum frequency was 87, so 10 years/division will enable all classes to be shown on the histogram. For each class in the table, plot the frequency on the histogram.

Science