Finding the Fourth Proportional to 15,721.52, 21,695.72 and 8,648.04

Step by Step Solution

1. Step 1: Write the proportion equation
   15,721.52 : 21,695.72 = 8,648.04 : x
2. Step 2: Convert to fraction form
   15,721.52/21,695.72 = 8,648.04/x
3. Step 3: Cross multiply
   15,721.52x = 21,695.72 × 8,648.04
4. Step 4: Simplify right side
   15,721.52x = 187,625,454.39
5. Step 5: Solve for x
   x = 187,625,454.39/15,721.52
6. Step 6: Final answer
   x = 11,934.31