Finding the Fourth Proportional to 21,180, 29,229.12 and 13,740.96

Step by Step Solution

1. Step 1: Write the proportion equation
   21,180 : 29,229.12 = 13,740.96 : x
2. Step 2: Convert to fraction form
   21,180/29,229.12 = 13,740.96/x
3. Step 3: Cross multiply
   21,180x = 29,229.12 × 13,740.96
4. Step 4: Simplify right side
   21,180x = 401,636,168.76
5. Step 5: Solve for x
   x = 401,636,168.76/21,180
6. Step 6: Final answer
   x = 18,962.99