Finding the Fourth Proportional to 653,123, 901,734.78 and 398,621.72

Step by Step Solution

1. Step 1: Write the proportion equation
   653,123 : 901,734.78 = 398,621.72 : x
2. Step 2: Convert to fraction form
   653,123/901,734.78 = 398,621.72/x
3. Step 3: Cross multiply
   653,123x = 901,734.78 × 398,621.72
4. Step 4: Simplify right side
   653,123x = 359,451,068,987.42
5. Step 5: Solve for x
   x = 359,451,068,987.42/653,123
6. Step 6: Final answer
   x = 550,357.39