Finding the Fourth Proportional to 2,086.24, 3,129.92 and 1,221.12

Step by Step Solution

1. Step 1: Write the proportion equation
   2,086.24 : 3,129.92 = 1,221.12 : x
2. Step 2: Convert to fraction form
   2,086.24/3,129.92 = 1,221.12/x
3. Step 3: Cross multiply
   2,086.24x = 3,129.92 × 1,221.12
4. Step 4: Simplify right side
   2,086.24x = 3,822,007.91
5. Step 5: Solve for x
   x = 3,822,007.91/2,086.24
6. Step 6: Final answer
   x = 1,832.01