Finding the Third Proportional to 8,780 and 13,260

Step by Step Solution

1. Step 1: Write the proportion equation
   8,780 : 13,260 = 13,260 : x
2. Step 2: Convert to fraction form
   8,780/13,260 = 13,260/x
3. Step 3: Cross multiply
   8,780x = 13,260 × 13,260
4. Step 4: Simplify right side
   8,780x = 175,827,600
5. Step 5: Solve for x
   x = 175,827,600/8,780
6. Step 6: Final answer
   x = 20,025.92