Finding the Third Proportional to 12,960 and 19,821

Step by Step Solution

1. Step 1: Write the proportion equation
   12,960 : 19,821 = 19,821 : x
2. Step 2: Convert to fraction form
   12,960/19,821 = 19,821/x
3. Step 3: Cross multiply
   12,960x = 19,821 × 19,821
4. Step 4: Simplify right side
   12,960x = 392,872,041
5. Step 5: Solve for x
   x = 392,872,041/12,960
6. Step 6: Final answer
   x = 30,314.20