Question: Look at the data set below.
17 21 31 9 12 41 53 100 40
If you arrange this data in increasing order (that is, from smallest to largest),
you can find the _______ by looking at the value in the middle of the list.
What word is missing in the sentence above?
A Mean
B Range
C Mode
D Median
1. **State the problem:** We have the data set $$17, 21, 31, 9, 12, 41, 53, 100, 40$$ and need to find the missing word in the sentence: "If you arrange this data in increasing order, you can find the _______ by looking at the value in the middle of the list."
2. **Arrange the data in increasing order:**
$$9, 12, 17, 21, 31, 40, 41, 53, 100$$
3. **Identify the middle value:** Since there are 9 numbers (an odd number), the middle value is the 5th number in the ordered list.
4. **Find the 5th number:** The 5th number is $$31$$.
5. **Recall definitions:**
- Mean is the average of all numbers.
- Range is the difference between the largest and smallest values.
- Mode is the most frequent value.
- Median is the middle value when data is ordered.
6. **Conclusion:** The missing word is **Median** because it is the value in the middle of the ordered list.
**Final answer:** D Median