Finding the Fourth Proportional to 2,139.72, 3,209.68 and 1,043.92

Step by Step Solution

1. Step 1: Write the proportion equation
   2,139.72 : 3,209.68 = 1,043.92 : x
2. Step 2: Convert to fraction form
   2,139.72/3,209.68 = 1,043.92/x
3. Step 3: Cross multiply
   2,139.72x = 3,209.68 × 1,043.92
4. Step 4: Simplify right side
   2,139.72x = 3,350,649.15
5. Step 5: Solve for x
   x = 3,350,649.15/2,139.72
6. Step 6: Final answer
   x = 1,565.93