Finding the Fourth Proportional to 402,766.56, 555,798.82 and 221,486.12

Step by Step Solution

1. Step 1: Write the proportion equation
   402,766.56 : 555,798.82 = 221,486.12 : x
2. Step 2: Convert to fraction form
   402,766.56/555,798.82 = 221,486.12/x
3. Step 3: Cross multiply
   402,766.56x = 555,798.82 × 221,486.12
4. Step 4: Simplify right side
   402,766.56x = 123,101,724,142.38
5. Step 5: Solve for x
   x = 123,101,724,142.38/402,766.56
6. Step 6: Final answer
   x = 305,640.38