Consider the following dataset: 22, 29, 31, 30, 22, 24, 18, 20, 25. What is the third quartile’s value? Round to the nearest tenth if necessary
To find the third quartile (Q3), we need to arrange the dataset in ascending order:
18, 20, 22, 22, 24, 25, 29, 30, 31
There are 9 numbers in this dataset, so Q3 is the value that separates the highest 25% of the numbers from the rest. To find Q3, we need to find the median of the upper half of the dataset:
25, 29, 30, 31
Since there are an even number of numbers in this subset, we take the average of the two middle numbers:
(Q3) = (29 + 30) / 2 = 29.5
Therefore, the third quartile's value is 29.5.