Finding the Fourth Proportional to 387,100.72, 580,553.64 and 137,724.40

Step by Step Solution

1. Step 1: Write the proportion equation
   387,100.72 : 580,553.64 = 137,724.40 : x
2. Step 2: Convert to fraction form
   387,100.72/580,553.64 = 137,724.40/x
3. Step 3: Cross multiply
   387,100.72x = 580,553.64 × 137,724.40
4. Step 4: Simplify right side
   387,100.72x = 79,956,401,736.82
5. Step 5: Solve for x
   x = 79,956,401,736.82/387,100.72
6. Step 6: Final answer
   x = 206,551.93