Finding the Fourth Proportional to 15,665.91, 21,618.79 and 8,592.31

Step by Step Solution

1. Step 1: Write the proportion equation
   15,665.91 : 21,618.79 = 8,592.31 : x
2. Step 2: Convert to fraction form
   15,665.91/21,618.79 = 8,592.31/x
3. Step 3: Cross multiply
   15,665.91x = 21,618.79 × 8,592.31
4. Step 4: Simplify right side
   15,665.91x = 185,755,345.50
5. Step 5: Solve for x
   x = 185,755,345.50/15,665.91
6. Step 6: Final answer
   x = 11,857.30