Finding the Fourth Proportional to 15,665.61, 21,618.24 and 8,859.54

Step by Step Solution

1. Step 1: Write the proportion equation
   15,665.61 : 21,618.24 = 8,859.54 : x
2. Step 2: Convert to fraction form
   15,665.61/21,618.24 = 8,859.54/x
3. Step 3: Cross multiply
   15,665.61x = 21,618.24 × 8,859.54
4. Step 4: Simplify right side
   15,665.61x = 191,527,662.01
5. Step 5: Solve for x
   x = 191,527,662.01/15,665.61
6. Step 6: Final answer
   x = 12,225.99