To construct the boxplot and identify the 5-number summary for the given speed dating ratings, we will first determine the five numbers: minimum, first quartile (Q1), median (Q2), third quartile (Q3), and maximum.
Given Data:
2.0, 3.0, 3.5, 4.5, 5.5, 5.5, 6.5, 6.5, 6.5, 6.5, 6.5, 7.5, 8.5, 9.5, 9.5, 9.5, 10.0, 10.0, 10.0, 10.0
Step 1: Sort the Data
The ratings are already sorted in ascending order.
Step 2: Identify the 5-number summary
- Minimum: The smallest value = 2.0
- Maximum: The largest value = 10.0
- Median (Q2): The middle value. For n = 20 (even), the median is the average of the 10th and 11th values.
- 10th value = 6.5
- 11th value = 6.5
- Median \( (Q2) = \frac{6.5 + 6.5}{2} = 6.5 \)
- First Quartile (Q1): The median of the first half (first 10 values).
- First half: 2.0, 3.0, 3.5, 4.5, 5.5, 5.5, 6.5, 6.5, 6.5, 6.5
- Median of this set = average of the 5th and 6th values (5.5 and 5.5)
- First Quartile \( (Q1) = \frac{5.5 + 5.5}{2} = 5.5 \)
- Third Quartile (Q3): The median of the second half (last 10 values).
- Second half: 6.5, 6.5, 7.5, 8.5, 9.5, 9.5, 9.5, 10.0, 10.0, 10.0
- Median of this set = average of the 5th and 6th values (9.5 and 9.5)
- Third Quartile \( (Q3) = \frac{9.5 + 9.5}{2} = 9.5 \)
5-number summary:
- Minimum: 2.0
- Q1: 5.5
- Median (Q2): 6.5
- Q3: 9.5
- Maximum: 10.0
Thus, the 5-number summary is: 2.0, 5.5, 6.5, 9.5, 10.0
Part 1
The 5-number summary is:
- Minimum: 2.0
- Q1: 5.5
- Median: 6.5
- Q3: 9.5
- Maximum: 10.0
Part 2: Constructing the Box Plot
- The boxplot will have:
- The box stretching from Q1 (5.5) to Q3 (9.5)
- The median line inside the box at 6.5
- "Whiskers" extending from the minimum (2.0) to the maximum (10.0)
Identify the correct boxplot:
Let's analyze the options:
- Option A: Box from 4.5 to 9.75 is incorrect; whiskers don't match.
- Option B: Box from 4.5 to 8.5 is incorrect; whiskers don't match.
- Option C: Box from 5.5 to 9.5, median at 6.5, and extends from 2 to 10 are correct.
- Option D: No details available here, but if it's not option C, it's likely incorrect.
Conclusion:
The correct answer for the 5-number summary is: 2.0, 5.5, 6.5, 9.5, 10.0
The best boxplot that represents the data is Option C.