Question

Which of the following is not a valid description of an outlier?

a) A data value several standard deviations from the mean.
b) A data value that lies below Q1 or above Q3
c) A data value that is very unusual
d) A data value beyond the outer fences

Answer 1

An outlier is a data value that is very unusual and lies beyond the outer fences. It is not a valid description to say that an outlier is a data value several standard deviations from the mean or a data value that lies below Q1 or above Q3.

Step-by-step explanation:

An outlier is a data value that is very unusual and lies beyond the outer fences. It is not a valid description to say that an outlier is a data value several standard deviations from the mean or a data value that lies below Q1 or above Q3.

To identify outliers, we can use the interquartile range (IQR). The IQR is the range between the first quartile (Q1) and the third quartile (Q3). Any value that is below Q1 - 1.5 * IQR or above Q3 + 1.5 * IQR is considered an outlier.