What is the first quartile of the following data set

The first quartile, Q1, is the median of {3, 5, 7, 8}. Since there is an even number of values, we need the mean of the middle two values to find the first quartile:.

Step-by-step explanation:

Example 1: Find the first and third quartiles of the set {3, 7, 8, 5, 12, 14, 21, 15, 18, 14}