Finding the Fourth Proportional to 15,499.92, 21,389.90 and 8,426.35

Step by Step Solution

1. Step 1: Write the proportion equation
   15,499.92 : 21,389.90 = 8,426.35 : x
2. Step 2: Convert to fraction form
   15,499.92/21,389.90 = 8,426.35/x
3. Step 3: Cross multiply
   15,499.92x = 21,389.90 × 8,426.35
4. Step 4: Simplify right side
   15,499.92x = 180,238,783.87
5. Step 5: Solve for x
   x = 180,238,783.87/15,499.92
6. Step 6: Final answer
   x = 11,628.37