Solution :
Third quartile is the median of the second half part of the data .
Third quartile = 7.97
Locate the third quartile in the following data set: 7.69 7.72 7.8 7.86 7.90 7.94 7.97 8.06 8.09
Locate the first quartile in the following data set: 7.69 7.70 7.82 7.86 7.90 7.94 7.97 8.06 8.09