Finding the Third Proportional to 12,920 and 20,558

Step by Step Solution

1. Step 1: Write the proportion equation
   12,920 : 20,558 = 20,558 : x
2. Step 2: Convert to fraction form
   12,920/20,558 = 20,558/x
3. Step 3: Cross multiply
   12,920x = 20,558 × 20,558
4. Step 4: Simplify right side
   12,920x = 422,631,364
5. Step 5: Solve for x
   x = 422,631,364/12,920
6. Step 6: Final answer
   x = 32,711.41