Finding the Fourth Proportional to 3,921.31, 5,411.47 and 2,152.91

Step by Step Solution

1. Step 1: Write the proportion equation
   3,921.31 : 5,411.47 = 2,152.91 : x
2. Step 2: Convert to fraction form
   3,921.31/5,411.47 = 2,152.91/x
3. Step 3: Cross multiply
   3,921.31x = 5,411.47 × 2,152.91
4. Step 4: Simplify right side
   3,921.31x = 11,650,407.88
5. Step 5: Solve for x
   x = 11,650,407.88/3,921.31
6. Step 6: Final answer
   x = 2,971.05