Finding the Fourth Proportional to 21,131.69, 29,157.98 and 12,179.57

Step by Step Solution

1. Step 1: Write the proportion equation
   21,131.69 : 29,157.98 = 12,179.57 : x
2. Step 2: Convert to fraction form
   21,131.69/29,157.98 = 12,179.57/x
3. Step 3: Cross multiply
   21,131.69x = 29,157.98 × 12,179.57
4. Step 4: Simplify right side
   21,131.69x = 355,131,451.78
5. Step 5: Solve for x
   x = 355,131,451.78/21,131.69
6. Step 6: Final answer
   x = 16,805.64