Finding the Fourth Proportional to 423,613.35, 635,285.42 and 139,238.28

Step by Step Solution

1. Step 1: Write the proportion equation
   423,613.35 : 635,285.42 = 139,238.28 : x
2. Step 2: Convert to fraction form
   423,613.35/635,285.42 = 139,238.28/x
3. Step 3: Cross multiply
   423,613.35x = 635,285.42 × 139,238.28
4. Step 4: Simplify right side
   423,613.35x = 88,456,049,189.88
5. Step 5: Solve for x
   x = 88,456,049,189.88/423,613.35
6. Step 6: Final answer
   x = 208,813.18