Finding the Fourth Proportional to 406,019.52, 609,069.96 and 139,744.80

Step by Step Solution

1. Step 1: Write the proportion equation
   406,019.52 : 609,069.96 = 139,744.80 : x
2. Step 2: Convert to fraction form
   406,019.52/609,069.96 = 139,744.80/x
3. Step 3: Cross multiply
   406,019.52x = 609,069.96 × 139,744.80
4. Step 4: Simplify right side
   406,019.52x = 85,114,359,746.21
5. Step 5: Solve for x
   x = 85,114,359,746.21/406,019.52
6. Step 6: Final answer
   x = 209,631.20