Finding the Fourth Proportional to 415,640.72, 623,267.31 and 215,907.50

Step by Step Solution

1. Step 1: Write the proportion equation
   415,640.72 : 623,267.31 = 215,907.50 : x
2. Step 2: Convert to fraction form
   415,640.72/623,267.31 = 215,907.50/x
3. Step 3: Cross multiply
   415,640.72x = 623,267.31 × 215,907.50
4. Step 4: Simplify right side
   415,640.72x = 134,568,086,733.83
5. Step 5: Solve for x
   x = 134,568,086,733.83/415,640.72
6. Step 6: Final answer
   x = 323,760.59