What is the interquartile range of this data set?2, 5, 9, 11, 18, 30, 42, 48, 55, 73, 81A.79B.21C.46D.25

To find the interquartile range (IQR), we first need to find the lower quartile (Q1) and the upper quartile (Q3).

Step 1: Arrange the data in ascending order, which is already done.

Step 2: Find the median. The median is the middle number of a sorted list. If the list has an odd number of observations, the median is the middle number. If the list has an even number of observations, the median is the average of the two middle numbers. In this case, we have 11 numbers, so the median is the 6th number, which is 30.

Step 3: Find Q1 and Q3. Q1 is the median of the first half of the data, and Q3 is the median of the second half of the data.

For Q1, we take the first half of the data: 2, 5, 9, 11, 18. The median of this set is 9.

For Q3, we take the second half of the data: 42, 48, 55, 73, 81. The median of this set is 55.

Step 4: Subtract Q1 from Q3 to find the IQR.

IQR = Q3 - Q1 = 55 - 9 = 46

So, the interquartile range of this data set is 46 (Option C).