Finding the Fourth Proportional to 21,356.33, 29,469.42 and 12,402.05

Step by Step Solution

1. Step 1: Write the proportion equation
   21,356.33 : 29,469.42 = 12,402.05 : x
2. Step 2: Convert to fraction form
   21,356.33/29,469.42 = 12,402.05/x
3. Step 3: Cross multiply
   21,356.33x = 29,469.42 × 12,402.05
4. Step 4: Simplify right side
   21,356.33x = 365,481,072.96
5. Step 5: Solve for x
   x = 365,481,072.96/21,356.33
6. Step 6: Final answer
   x = 17,113.48