Finding the Fourth Proportional to 21,729.96, 29,980.32 and 12,168.42

Step by Step Solution

1. Step 1: Write the proportion equation
   21,729.96 : 29,980.32 = 12,168.42 : x
2. Step 2: Convert to fraction form
   21,729.96/29,980.32 = 12,168.42/x
3. Step 3: Cross multiply
   21,729.96x = 29,980.32 × 12,168.42
4. Step 4: Simplify right side
   21,729.96x = 364,812,975.59
5. Step 5: Solve for x
   x = 364,812,975.59/21,729.96
6. Step 6: Final answer
   x = 16,788.48