Finding the Fourth Proportional to 405,498.90, 608,340.72 and 215,859.33

Step by Step Solution

1. Step 1: Write the proportion equation
   405,498.90 : 608,340.72 = 215,859.33 : x
2. Step 2: Convert to fraction form
   405,498.90/608,340.72 = 215,859.33/x
3. Step 3: Cross multiply
   405,498.90x = 608,340.72 × 215,859.33
4. Step 4: Simplify right side
   405,498.90x = 131,316,020,230.92
5. Step 5: Solve for x
   x = 131,316,020,230.92/405,498.90
6. Step 6: Final answer
   x = 323,838.17