5 number summary

The 5 number summary consists of five key statistics that provide a quick overview of a dataset: minimum, first quartile (Q1), median (Q2), third quartile (Q3), and maximum.

To find the median, arrange the data in ascending order and locate the middle value. If there is an even number of observations, the median is the average of the two middle values.

The minimum is the smallest value in a dataset.

The maximum is the largest value in a dataset.

The first quartile (Q1) is the median of the lower half of the dataset, representing the 25th percentile.

The third quartile (Q3) is the median of the upper half of the dataset, representing the 75th percentile.

To calculate the mean, sum all the values in the dataset and divide by the number of values.

The mean is the average of all values, while the median is the middle value when the data is ordered. The mean can be affected by outliers, whereas the median is more robust.

An outlier is a value that is significantly higher or lower than the other values in a dataset, which can skew the mean.

Outliers can be identified using the interquartile range (IQR). Any value that is below Q1 - 1.5*IQR or above Q3 + 1.5*IQR is considered an outlier.