Finding the Fourth Proportional to 99,768.72, 137,680.92 and 55,056.72

Step by Step Solution

1. Step 1: Write the proportion equation
   99,768.72 : 137,680.92 = 55,056.72 : x
2. Step 2: Convert to fraction form
   99,768.72/137,680.92 = 55,056.72/x
3. Step 3: Cross multiply
   99,768.72x = 137,680.92 × 55,056.72
4. Step 4: Simplify right side
   99,768.72x = 7,580,259,861.78
5. Step 5: Solve for x
   x = 7,580,259,861.78/99,768.72
6. Step 6: Final answer
   x = 75,978.32