Finding the Fourth Proportional to 15,731.72, 21,709.37 and 8,561.33

Step by Step Solution

1. Step 1: Write the proportion equation
   15,731.72 : 21,709.37 = 8,561.33 : x
2. Step 2: Convert to fraction form
   15,731.72/21,709.37 = 8,561.33/x
3. Step 3: Cross multiply
   15,731.72x = 21,709.37 × 8,561.33
4. Step 4: Simplify right side
   15,731.72x = 185,860,929.31
5. Step 5: Solve for x
   x = 185,860,929.31/15,731.72
6. Step 6: Final answer
   x = 11,814.41