Finding the Fourth Proportional to 99,151.96, 136,790.78 and 56,687.72

Step by Step Solution

1. Step 1: Write the proportion equation
   99,151.96 : 136,790.78 = 56,687.72 : x
2. Step 2: Convert to fraction form
   99,151.96/136,790.78 = 56,687.72/x
3. Step 3: Cross multiply
   99,151.96x = 136,790.78 × 56,687.72
4. Step 4: Simplify right side
   99,151.96x = 7,754,357,435.22
5. Step 5: Solve for x
   x = 7,754,357,435.22/99,151.96
6. Step 6: Final answer
   x = 78,206.80