01
Mar
Box Plot Normal Distribution. The answer depends on the true underlying probability distribution of. The outliers also indicate a skew. A line inside the rectangle shows the median and whiskers above and below the box show the locations of the minimum and maximum values. Normal Distribution or Symmetric Distribution.
For a distribution that is positively skewed the box plot will show the median closer to the lower or bottom quartile. Even when they are not we tend to assume that they are for better or worse. Sort the values before plotting in the normal distribution graph to get a better curve-shaped graph in excel. The mean will be about the same as the median and the box plot will look symmetric. The plots show that the distribution between the data points is different. One way to understand a box plot is to think of what a box plot of data from a normal distribution will look like.
The first and second quartiles are very short compared to the first and second quartiles of the normal distribution example and compared to the third and fourth quartile of the log normal distribution.
If the distance from the median to the maximum is greater than the distance from the median to the minimum then the box plot. Box limits indicate the range of the central 50 of the data with a central line marking the median value. If the distribution is skewed to the right most values are small but there are a few exceptionally large ones. You can see the median value of the boxplot is accurate and the quartile markers the edges of the box show the skew. We can also identify the skewness of our data by observing the shape of the box plot. It DOES NOT show mean in the Box Plot unless its a Normal Distribution which meanmedian.