Finding the Fourth Proportional to 99,489.72, 137,288.89 and 56,470.09

Step by Step Solution

1. Step 1: Write the proportion equation
   99,489.72 : 137,288.89 = 56,470.09 : x
2. Step 2: Convert to fraction form
   99,489.72/137,288.89 = 56,470.09/x
3. Step 3: Cross multiply
   99,489.72x = 137,288.89 × 56,470.09
4. Step 4: Simplify right side
   99,489.72x = 7,752,715,641.44
5. Step 5: Solve for x
   x = 7,752,715,641.44/99,489.72
6. Step 6: Final answer
   x = 77,924.79