Finding the Fourth Proportional to 21,120.79, 29,150.31 and 12,173.50

Step by Step Solution

1. Step 1: Write the proportion equation
   21,120.79 : 29,150.31 = 12,173.50 : x
2. Step 2: Convert to fraction form
   21,120.79/29,150.31 = 12,173.50/x
3. Step 3: Cross multiply
   21,120.79x = 29,150.31 × 12,173.50
4. Step 4: Simplify right side
   21,120.79x = 354,861,298.79
5. Step 5: Solve for x
   x = 354,861,298.79/21,120.79
6. Step 6: Final answer
   x = 16,801.52