To find the interquartile range, we first need to determine the quartiles. In this data set {9, 8, 6, 6, 6, 7, 1, 2, 6, 8}, the median is 6. To find the lower quartile (Q1), we take the median of the lower half of the data, which is {1, 2, 6, 6}. The lower quartile is 2. To find the upper quartile (Q3), we take the median of the upper half of the data, which is {6, 7, 8, 9}. The upper quartile is 8.
The interquartile range is then calculated by subtracting Q1 from Q3: 8 - 2 = 6. Therefore, the interquartile range for this data set is 6.
