Finding the Fourth Proportional to 3,907.56, 5,392.32 and 2,139.12

Step by Step Solution

1. Step 1: Write the proportion equation
   3,907.56 : 5,392.32 = 2,139.12 : x
2. Step 2: Convert to fraction form
   3,907.56/5,392.32 = 2,139.12/x
3. Step 3: Cross multiply
   3,907.56x = 5,392.32 × 2,139.12
4. Step 4: Simplify right side
   3,907.56x = 11,534,819.56
5. Step 5: Solve for x
   x = 11,534,819.56/3,907.56
6. Step 6: Final answer
   x = 2,951.92