Rearrange data in increasing order: 6,7,7,7,8,8,8,9,9 and 11
First quartile (ungrouped data) = n + 14\;\frac{n\;+\;1}{4}4n+1th value
= 114\;\frac{11}{4}411
= 2.75th value
= 7 + 72\;\frac{7\;+\;7}{2}27+7
= 7.0
