Finding the Fourth Proportional to 15,404.81, 21,259.61 and 8,687.98

Step by Step Solution

1. Step 1: Write the proportion equation
   15,404.81 : 21,259.61 = 8,687.98 : x
2. Step 2: Convert to fraction form
   15,404.81/21,259.61 = 8,687.98/x
3. Step 3: Cross multiply
   15,404.81x = 21,259.61 × 8,687.98
4. Step 4: Simplify right side
   15,404.81x = 184,703,035.06
5. Step 5: Solve for x
   x = 184,703,035.06/15,404.81
6. Step 6: Final answer
   x = 11,989.96