To solve the given problem, we need to follow these steps:
- Find the quartiles: Calculate the first quartile (Q1), the second quartile (Q2, which is the median), and the third quartile (Q3) of the data set.
- Find the interquartile range (IQR): Calculate the difference between the third quartile (Q3) and the first quartile (Q1).
- Identify any outliers: Determine if there are any outliers in the data set using the IQR. An outlier is any data point that is below Q1 - 1.5_IQR or above Q3 + 1.5_IQR.
First, we need to organize the data set in ascending order. Let's assume the data set provided is:
\[ \{3, 7, 8, 5, 12, 14, 21, 13, 18, 9\} \]
Sort the data set in ascending order:
\[ \{3, 5, 7, 8, 9, 12, 13, 14, 18, 21\} \]
To find the quartiles, we need to divide the data set into four equal parts.
The first quartile (\(Q_1\)) is the median of the first half of the data set. For the sorted data set:
\[ \{3, 5, 7, 8, 9\} \]
The median of this subset is:
\[ Q_1 = 7 \]
The second quartile (\(Q_2\)) is the median of the entire data set. For the sorted data set:
\[ \{3, 5, 7, 8, 9, 12, 13, 14, 18, 21\} \]
The median of this set is:
\[ Q_2 = 10.5 \]
The third quartile (\(Q_3\)) is the median of the second half of the data set. For the sorted data set:
\[ \{12, 13, 14, 18, 21\} \]
The median of this subset is:
\[ Q_3 = 14 \]
The interquartile range (IQR) is calculated as:
\[ \text{IQR} = Q_3 - Q_1 \]
Substituting the values:
\[ \text{IQR} = 14 - 7 = 7 \]
To identify outliers, we use the following formulas:
\[ \text{Lower Bound} = Q_1 - 1.5 \times \text{IQR} \]
\[ \text{Upper Bound} = Q_3 + 1.5 \times \text{IQR} \]
Substituting the values:
\[ \text{Lower Bound} = 7 - 1.5 \times 7 = 7 - 10.5 = -3.5 \]
\[ \text{Upper Bound} = 14 + 1.5 \times 7 = 14 + 10.5 = 24.5 \]
Any data points outside the range \([-3.5, 24.5]\) are considered outliers. Since all data points \(\{3, 5, 7, 8, 9, 12, 13, 14, 18, 21\}\) fall within this range, there are no outliers.
\[
\boxed{Q_1 = 7}
\]
\[
\boxed{Q_2 = 10.5}
\]
\[
\boxed{Q_3 = 14}
\]
\[
\boxed{\text{IQR} = 7}
\]
\[
\boxed{\text{B. There are no outliers in the data set.}}
\]