How to find the 20th and 80th percentile of a data set

The video tutorial explains how to arrange data in order to find the median and calculate percentiles. It demonstrates the process of ordering values from least to greatest and highlights the importance of maintaining the same number of values before and after rearrangement. The tutorial then focuses on calculating the 20th and 80th percentiles by multiplying the percentile value by the total number of data points and identifying the corresponding value in the ordered list. The explanation emphasizes understanding percentiles as a way to determine the percentage of data below a certain value.

Explain the process of arranging values from least to greatest.

What is the significance of ensuring that the data set is in order before calculating percentiles?