Finding the Fourth Proportional to 643,200.10, 887,557.98 and 356,719.30

Step by Step Solution

1. Step 1: Write the proportion equation
   643,200.10 : 887,557.98 = 356,719.30 : x
2. Step 2: Convert to fraction form
   643,200.10/887,557.98 = 356,719.30/x
3. Step 3: Cross multiply
   643,200.10x = 887,557.98 × 356,719.30
4. Step 4: Simplify right side
   643,200.10x = 316,609,061,335.01
5. Step 5: Solve for x
   x = 316,609,061,335.01/643,200.10
6. Step 6: Final answer
   x = 492,240.38