Finding the Fourth Proportional to 402,977.43, 556,086.89 and 221,660.09

Step by Step Solution

1. Step 1: Write the proportion equation
   402,977.43 : 556,086.89 = 221,660.09 : x
2. Step 2: Convert to fraction form
   402,977.43/556,086.89 = 221,660.09/x
3. Step 3: Cross multiply
   402,977.43x = 556,086.89 × 221,660.09
4. Step 4: Simplify right side
   402,977.43x = 123,262,266,196.49
5. Step 5: Solve for x
   x = 123,262,266,196.49/402,977.43
6. Step 6: Final answer
   x = 305,878.84