Finding the Fourth Proportional to 3,921.52, 5,411.76 and 2,153.12

Step by Step Solution

1. Step 1: Write the proportion equation
   3,921.52 : 5,411.76 = 2,153.12 : x
2. Step 2: Convert to fraction form
   3,921.52/5,411.76 = 2,153.12/x
3. Step 3: Cross multiply
   3,921.52x = 5,411.76 × 2,153.12
4. Step 4: Simplify right side
   3,921.52x = 11,652,168.69
5. Step 5: Solve for x
   x = 11,652,168.69/3,921.52
6. Step 6: Final answer
   x = 2,971.34