Finding the Fourth Proportional to 21,608.50, 29,822.37 and 12,178.78

Step by Step Solution

1. Step 1: Write the proportion equation
   21,608.50 : 29,822.37 = 12,178.78 : x
2. Step 2: Convert to fraction form
   21,608.50/29,822.37 = 12,178.78/x
3. Step 3: Cross multiply
   21,608.50x = 29,822.37 × 12,178.78
4. Step 4: Simplify right side
   21,608.50x = 363,200,083.31
5. Step 5: Solve for x
   x = 363,200,083.31/21,608.50
6. Step 6: Final answer
   x = 16,808.20