Finding the Fourth Proportional to 221,143.30, 331,518.56 and 86,176.10

Step by Step Solution

1. Step 1: Write the proportion equation
   221,143.30 : 331,518.56 = 86,176.10 : x
2. Step 2: Convert to fraction form
   221,143.30/331,518.56 = 86,176.10/x
3. Step 3: Cross multiply
   221,143.30x = 331,518.56 × 86,176.10
4. Step 4: Simplify right side
   221,143.30x = 28,568,976,976.33
5. Step 5: Solve for x
   x = 28,568,976,976.33/221,143.30
6. Step 6: Final answer
   x = 129,187.62