Finding the Fourth Proportional to 643,460.45, 888,081.72 and 357,072.80

Step by Step Solution

1. Step 1: Write the proportion equation
   643,460.45 : 888,081.72 = 357,072.80 : x
2. Step 2: Convert to fraction form
   643,460.45/888,081.72 = 357,072.80/x
3. Step 3: Cross multiply
   643,460.45x = 888,081.72 × 357,072.80
4. Step 4: Simplify right side
   643,460.45x = 317,109,826,389.22
5. Step 5: Solve for x
   x = 317,109,826,389.22/643,460.45
6. Step 6: Final answer
   x = 492,819.45