Skewed data are not equally distributed on both sides of the distribution—it is not a symmetrical distribution. Use a histogram to easily see whether your data are skewed.

When you refer to skewed data, you can describe it as either right skewed or left skewed.

Data are skewed right when most of the data are on the left side of the graph and the long skinny tail extends to the right.

Data are skewed left when most of the data are on the right side of the graph and the long skinny tail extends to the left.

If your data are skewed, the mean can be misleading because the most common values in the distribution might not be near the mean. Additionally, skewed data can affect which types of analyses are valid to perform.

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