Finding the Fourth Proportional to 3,921.55, 5,411.81 and 2,153.25

Step by Step Solution

1. Step 1: Write the proportion equation
   3,921.55 : 5,411.81 = 2,153.25 : x
2. Step 2: Convert to fraction form
   3,921.55/5,411.81 = 2,153.25/x
3. Step 3: Cross multiply
   3,921.55x = 5,411.81 × 2,153.25
4. Step 4: Simplify right side
   3,921.55x = 11,652,985.27
5. Step 5: Solve for x
   x = 11,652,985.27/3,921.55
6. Step 6: Final answer
   x = 2,971.53