How do I read a box-and-whisker plot ?? Please help with example if you can?? Thank you so much.
help with above? I am lost when after I make the stem leaf plot when I get the data? The average from it.
I taught math for 35 years and must admit I had no idea what a "box and whisker" plot is,
so I looked it up
Interesting that Sal Khan has a nice video of the thing
https://www.khanacademy.org/math/probability/descriptive-statistics/Box-and-whisker%20plots/v/box-and-whisker-plots
To read a box-and-whisker plot, you need to understand the different components and their meanings. Let's go through it step by step with an example:
1. The box: The box in the plot represents the interquartile range (IQR), which is the range between the first quartile (Q1) and the third quartile (Q3). It contains the middle 50% of the data. The length of the box reflects the spread of the data within this range.
2. The line inside the box: This line represents the median, which is the middle value of the dataset. Half of the data points are below this line, and half are above it.
3. The whiskers: The whiskers extend from the box and represent the maximum and minimum values of the dataset, excluding any outliers.
4. Outliers: Points that fall outside the whiskers are considered outliers and are displayed as individual data points. They are typically marked with dots or other symbols.
Now, let's consider an example to illustrate how to interpret a box-and-whisker plot:
Suppose we have a box-and-whisker plot for the scores of two basketball teams - Team A and Team B. The plot shows the following information:
- For Team A, the box spans from 70 to 80, with a median of 75.
- For Team B, the box spans from 60 to 90, with a median of 80.
- The whiskers for both teams extend beyond the boxes, indicating that there are no outliers.
- The range of scores for Team A is from 60 to 85, while for Team B it is from 55 to 95.
From this information, we can gather that:
- Team A has a narrower spread of scores compared to Team B, as the box for Team A is shorter.
- The median score for Team A is lower than that of Team B.
- Team B has a larger range of scores, indicating more variability in performance.
By understanding these components and analyzing the values, you can draw conclusions about the distribution and comparison of datasets represented by the box-and-whisker plot.