Finding the Fourth Proportional to 99,121.10, 136,789.15 and 56,100.59

Step by Step Solution

1. Step 1: Write the proportion equation
   99,121.10 : 136,789.15 = 56,100.59 : x
2. Step 2: Convert to fraction form
   99,121.10/136,789.15 = 56,100.59/x
3. Step 3: Cross multiply
   99,121.10x = 136,789.15 × 56,100.59
4. Step 4: Simplify right side
   99,121.10x = 7,673,951,196.40
5. Step 5: Solve for x
   x = 7,673,951,196.40/99,121.10
6. Step 6: Final answer
   x = 77,419.96