Finding the Fourth Proportional to 399,196.18, 550,808.46 and 229,397.50

Step by Step Solution

1. Step 1: Write the proportion equation
   399,196.18 : 550,808.46 = 229,397.50 : x
2. Step 2: Convert to fraction form
   399,196.18/550,808.46 = 229,397.50/x
3. Step 3: Cross multiply
   399,196.18x = 550,808.46 × 229,397.50
4. Step 4: Simplify right side
   399,196.18x = 126,354,083,702.85
5. Step 5: Solve for x
   x = 126,354,083,702.85/399,196.18
6. Step 6: Final answer
   x = 316,521.27