Final answer:
The Interquartile Range (IQR) is the spread of the middle 50% of the data, and for this dataset, it is 7. The third quartile (Q3) is the value below which 75% of the house prices fall, not the median or the highest value in the dataset.
Step-by-step explanation:
The Interquartile Range (IQR) is a measure of statistical dispersion, which tells us the range of the middle 50 percent of the data. It is calculated by subtracting the first quartile (Q1) from the third quartile (Q3), so for this data set, it would be 9 - 2, resulting in an IQR of 7. This number helps identify the variability of the central portion of the dataset and aids in identifying potential outliers. The third quartile (Q3) is not the median of the data set; rather, it is the value below which 75% of the data falls. This means that 75% of house prices fall below Q3, which makes option C the correct interpretation of Q3. It is a misconception that Q3 would represent the highest house price or that it represents the middle 25% of house prices; thus, options A, B, and D are incorrect. It specifically signifies the upper limit of the central 50% of the data.