Finding the Fourth Proportional to 321,105.08, 442,608.56 and 217,705.78

Step by Step Solution

1. Step 1: Write the proportion equation
   321,105.08 : 442,608.56 = 217,705.78 : x
2. Step 2: Convert to fraction form
   321,105.08/442,608.56 = 217,705.78/x
3. Step 3: Cross multiply
   321,105.08x = 442,608.56 × 217,705.78
4. Step 4: Simplify right side
   321,105.08x = 96,358,441,789.48
5. Step 5: Solve for x
   x = 96,358,441,789.48/321,105.08
6. Step 6: Final answer
   x = 300,083.83