Finding the Third Proportional to 8,439.75 and 12,589.88

Step by Step Solution

1. Step 1: Write the proportion equation
   8,439.75 : 12,589.88 = 12,589.88 : x
2. Step 2: Convert to fraction form
   8,439.75/12,589.88 = 12,589.88/x
3. Step 3: Cross multiply
   8,439.75x = 12,589.88 × 12,589.88
4. Step 4: Simplify right side
   8,439.75x = 158,504,952.52
5. Step 5: Solve for x
   x = 158,504,952.52/8,439.75
6. Step 6: Final answer
   x = 18,780.76