Finding the Fourth Proportional to 21,123.36, 29,146.69 and 12,628.92

Step by Step Solution

1. Step 1: Write the proportion equation
   21,123.36 : 29,146.69 = 12,628.92 : x
2. Step 2: Convert to fraction form
   21,123.36/29,146.69 = 12,628.92/x
3. Step 3: Cross multiply
   21,123.36x = 29,146.69 × 12,628.92
4. Step 4: Simplify right side
   21,123.36x = 368,091,216.27
5. Step 5: Solve for x
   x = 368,091,216.27/21,123.36
6. Step 6: Final answer
   x = 17,425.79