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In this section, we are going to be looking at comparing two box plots. There are many different points of comparison that you can make from two box plots and here are some of them:

Let’s have an example.

In this section, we are going to be looking at comparing two box plots. There are many different points of comparison that you can make from two box plots and here are some of them:

- Comparing the medians
- Comparing the ranges
- Comparing the interquartile ranges
- Compering the highest/ lowest values

Let’s have an example.

**Example 1 – Comparing Box Plots**

We are given two box plots for the performance of boys and girls in a test. The box plot for the boys is in green and the box plot for the girls is in purple. Comment on what the results show us about the difference between the performance of boys and girls on the test.

The first point of comparison that we can talk about is the highest and lowest values. We can see that the lowest score out of all of the individuals was a boy. Also, the highest score out of all of the individuals was a girl.

We can also comment about the range. The range is the difference between the largest and smallest value. On a box plot, the range is the distance between the far ends of the box plot. The range is larger for the boys compared with the girls.

Another point of comparison that we can make is about the interquartile range. The interquartile range is the upper quartile minus the lower quartile (IQR = UQ – LQ). On the box plot, the interquartile range is the distance between the start and end of the box part of the box plot. The boys have a smaller interquartile range.

The final point of comparison that we can make is about the medians. The median is the line inside the box part of the box plot. The median is higher for the girls than the boys

We can also comment about the range. The range is the difference between the largest and smallest value. On a box plot, the range is the distance between the far ends of the box plot. The range is larger for the boys compared with the girls.

Another point of comparison that we can make is about the interquartile range. The interquartile range is the upper quartile minus the lower quartile (IQR = UQ – LQ). On the box plot, the interquartile range is the distance between the start and end of the box part of the box plot. The boys have a smaller interquartile range.

The final point of comparison that we can make is about the medians. The median is the line inside the box part of the box plot. The median is higher for the girls than the boys

**End Note**

Usually questions like this will ask for two points of comparison. There will usually be more than two acceptable answers on the mark scheme. Therefore, you can write any two interesting points of comparison.