Finding the Fourth Proportional to 394,978.03, 545,068.20 and 213,689.38

Step by Step Solution

1. Step 1: Write the proportion equation
   394,978.03 : 545,068.20 = 213,689.38 : x
2. Step 2: Convert to fraction form
   394,978.03/545,068.20 = 213,689.38/x
3. Step 3: Cross multiply
   394,978.03x = 545,068.20 × 213,689.38
4. Step 4: Simplify right side
   394,978.03x = 116,475,285,715.72
5. Step 5: Solve for x
   x = 116,475,285,715.72/394,978.03
6. Step 6: Final answer
   x = 294,890.54