Question

Which is more affected by extreme observations, the mean or median? And how about the standard deviation or IQR?

• mean, standard deviation
• mean, IQR
• median, standard deviation
• median, IQR

Answer 1

Option (A): mean, standard deviation

> Mean is average value of a data set. If the upper extreme values are too large, the mean will shift to the right. If the lower extreme values are too small, the mean will shift to the left. Median is not affected by the extreme values as for median only the order of the values are matters.

The same goes for standard deviation. If the extreme values are too large or too small, the standard deviation increses greatly. The IQR will change only if the order of the data changes.

Thank you.