Finding the Fourth Proportional to 21,078.78, 29,091.60 and 12,126.12

Step by Step Solution

1. Step 1: Write the proportion equation
   21,078.78 : 29,091.60 = 12,126.12 : x
2. Step 2: Convert to fraction form
   21,078.78/29,091.60 = 12,126.12/x
3. Step 3: Cross multiply
   21,078.78x = 29,091.60 × 12,126.12
4. Step 4: Simplify right side
   21,078.78x = 352,768,232.59
5. Step 5: Solve for x
   x = 352,768,232.59/21,078.78
6. Step 6: Final answer
   x = 16,735.70