Finding the Fourth Proportional to 14,196.50, 21,313.60 and 12,129.78

Step by Step Solution

1. Step 1: Write the proportion equation
   14,196.50 : 21,313.60 = 12,129.78 : x
2. Step 2: Convert to fraction form
   14,196.50/21,313.60 = 12,129.78/x
3. Step 3: Cross multiply
   14,196.50x = 21,313.60 × 12,129.78
4. Step 4: Simplify right side
   14,196.50x = 258,529,279.01
5. Step 5: Solve for x
   x = 258,529,279.01/14,196.50
6. Step 6: Final answer
   x = 18,210.78