Finding the Fourth Proportional to 3,921.52, 5,411.58 and 2,128.92

Step by Step Solution

1. Step 1: Write the proportion equation
   3,921.52 : 5,411.58 = 2,128.92 : x
2. Step 2: Convert to fraction form
   3,921.52/5,411.58 = 2,128.92/x
3. Step 3: Cross multiply
   3,921.52x = 5,411.58 × 2,128.92
4. Step 4: Simplify right side
   3,921.52x = 11,520,820.89
5. Step 5: Solve for x
   x = 11,520,820.89/3,921.52
6. Step 6: Final answer
   x = 2,937.85