Question

Here is a sample data set (n=48) that is nearly normal (as can be seen in the histogram provided after the data set).

17.9	18.6	21.8	23.2	24.9	26	28.6	29.6
29.9	29.9	30.1	30.3	30.3	30.8	32.7	33
33.8	33.8	35.2	35.2	35.2	35.2	35.8	36.2
36.4	37	37.4	37.7	38.1	38.5	39.2	39.4
39.9	41.5	41.5	42	42	42.3	42.3	43.3
44.8	45.3	45.7	46.2	49.6	52.1	53.6	53.6

How many outliers are in this data set?
ans =

For this data set, classify anything beyond 2 standard deviations from the mean as a potential outlier.

Answer 1

Here the mean is

Standard deviation is

Anything beyond 2 standard deviations from the mean is

mean + 2 standard deviation =44.77

mean - 2 standard deviation =28.02

Those values which outside the interval (28.02,44.77) can be treated as an outlier

outliers are 17.6,18.6,21.8,23.2,24.9,26,44.8,45.3,45.7,46.2,49.6,52.1,53.6,53.6

The number of outliers is 14