Finding the Fourth Proportional to 2,139.20, 3,208.94 and 1,625.92

Step by Step Solution

1. Step 1: Write the proportion equation
   2,139.20 : 3,208.94 = 1,625.92 : x
2. Step 2: Convert to fraction form
   2,139.20/3,208.94 = 1,625.92/x
3. Step 3: Cross multiply
   2,139.20x = 3,208.94 × 1,625.92
4. Step 4: Simplify right side
   2,139.20x = 5,217,479.72
5. Step 5: Solve for x
   x = 5,217,479.72/2,139.20
6. Step 6: Final answer
   x = 2,438.99