Finding the Fourth Proportional to 15,787.71, 21,784.55 and 9,414.02

Step by Step Solution

1. Step 1: Write the proportion equation
   15,787.71 : 21,784.55 = 9,414.02 : x
2. Step 2: Convert to fraction form
   15,787.71/21,784.55 = 9,414.02/x
3. Step 3: Cross multiply
   15,787.71x = 21,784.55 × 9,414.02
4. Step 4: Simplify right side
   15,787.71x = 205,080,196.78
5. Step 5: Solve for x
   x = 205,080,196.78/15,787.71
6. Step 6: Final answer
   x = 12,989.86