Finding the Fourth Proportional to 425,732.64, 638,005.86 and 215,124.72

Step by Step Solution

1. Step 1: Write the proportion equation
   425,732.64 : 638,005.86 = 215,124.72 : x
2. Step 2: Convert to fraction form
   425,732.64/638,005.86 = 215,124.72/x
3. Step 3: Cross multiply
   425,732.64x = 638,005.86 × 215,124.72
4. Step 4: Simplify right side
   425,732.64x = 137,250,831,990.86
5. Step 5: Solve for x
   x = 137,250,831,990.86/425,732.64
6. Step 6: Final answer
   x = 322,387.38