Finding the Third Proportional to 8,623.13 and 12,789.56

Step by Step Solution

1. Step 1: Write the proportion equation
   8,623.13 : 12,789.56 = 12,789.56 : x
2. Step 2: Convert to fraction form
   8,623.13/12,789.56 = 12,789.56/x
3. Step 3: Cross multiply
   8,623.13x = 12,789.56 × 12,789.56
4. Step 4: Simplify right side
   8,623.13x = 163,572,908.94
5. Step 5: Solve for x
   x = 163,572,908.94/8,623.13
6. Step 6: Final answer
   x = 18,969.10