Finding the Fourth Proportional to 21,651.27, 29,878.17 and 12,090.89

Step by Step Solution

1. Step 1: Write the proportion equation
   21,651.27 : 29,878.17 = 12,090.89 : x
2. Step 2: Convert to fraction form
   21,651.27/29,878.17 = 12,090.89/x
3. Step 3: Cross multiply
   21,651.27x = 29,878.17 × 12,090.89
4. Step 4: Simplify right side
   21,651.27x = 361,253,584.18
5. Step 5: Solve for x
   x = 361,253,584.18/21,651.27
6. Step 6: Final answer
   x = 16,685.10