Finding the Fourth Proportional to 718,730,419.72, 991,848,640.56 and 388,705,558.72

Step by Step Solution

1. Step 1: Write the proportion equation
   718,730,419.72 : 991,848,640.56 = 388,705,558.72 : x
2. Step 2: Convert to fraction form
   718,730,419.72/991,848,640.56 = 388,705,558.72/x
3. Step 3: Cross multiply
   718,730,419.72x = 991,848,640.56 × 388,705,558.72
4. Step 4: Simplify right side
   718,730,419.72x = 385,537,079,994,547,264
5. Step 5: Solve for x
   x = 385,537,079,994,547,264/718,730,419.72
6. Step 6: Final answer
   x = 536,414,028.70