Outliers and Their Effects on Data

Front

What is an outlier in a data set?

Back

An outlier is a data point that differs significantly from other observations in a data set. It can skew the results of statistical analyses.

Front

How does an outlier affect the mean of a data set?

Back

An outlier can significantly increase or decrease the mean, making it unrepresentative of the majority of the data.

Front

What is the mean of a data set?

Back

The mean is the average of a set of numbers, calculated by adding all the values together and dividing by the number of values.

Front

What is the median of a data set?

Back

The median is the middle value when a data set is ordered from least to greatest. If there is an even number of observations, the median is the average of the two middle numbers.

Front

What is the range of a data set?

Back

The range is the difference between the highest and lowest values in a data set.

Front

How do you calculate the mean of a data set with an outlier?

Back

To calculate the mean with an outlier, add all values including the outlier and divide by the total number of values.

Front

What happens to the mean if an outlier is removed?

Back

Removing an outlier typically results in a mean that is more representative of the remaining data.

Front

What is the effect of adding a significantly high value to a data set?

Back

Adding a significantly high value (outlier) will increase the mean of the data set.

Front

What is the effect of adding a significantly low value to a data set?

Back

Adding a significantly low value (outlier) will decrease the mean of the data set.

Front

How does the presence of an outlier affect the median?

Back

The median is less affected by outliers than the mean, as it depends on the middle value(s) of the ordered data.