The mode refers to the values occurring with the highest frequency in our data set. If we are given a set of data values plotted in the form of a histogram then we can find the mode by the following steps. Let us understand this by looking at the following example. Consider the histogram given below:
Steps to find mode from histogram:
- Identify the bar with the greatest height in the histogram. Having the greatest height means that the mode lies within that class interval. In the above graph, the blue colored bar has the highest frequency of 25 and so the mode lies somewhere between the class interval 30-40.
- Join the upper left corner of the highest bar with the upper left corner of the succeding bar with a straight line. This means that we join the two orange dots in the above histogram.
- Similarly, we join upper right corner of the highest bar with the upper right corner of the preceeding bar with a straight line. This means that we join the two green dots in the above histogram.
- Mark the point where the two lines intersect. Draw a vertical line extending straight below that point. The values at which the line meets the x-axis give us the mode. in the above graph, the mode is equal to 35.