Step 1: Understanding the Concept:
For any distribution, there is an empirical relationship between the three measures of central tendency: Mean, Median, and Mode. Step 2: Key Formula or Approach:
\[ \text{Mode} = 3(\text{Median}) - 2(\text{Mean}) \] Step 3: Detailed Explanation:
1. Given: Mean = 12, Mode = 21.
2. Substitute the values into the empirical formula:
\[ 21 = 3(\text{Median}) - 2(12) \]
3. Solve for Median:
\[ 21 = 3(\text{Median}) - 24 \]
\[ 21 + 24 = 3(\text{Median}) \]
\[ 45 = 3(\text{Median}) \]
\[ \text{Median} = \frac{45}{3} = 15 \] Step 4: Final Answer:
The median of the data is 15.