Finding the Fourth Proportional to 21,120.30, 29,145.24 and 12,168.18

Step by Step Solution

1. Step 1: Write the proportion equation
   21,120.30 : 29,145.24 = 12,168.18 : x
2. Step 2: Convert to fraction form
   21,120.30/29,145.24 = 12,168.18/x
3. Step 3: Cross multiply
   21,120.30x = 29,145.24 × 12,168.18
4. Step 4: Simplify right side
   21,120.30x = 354,644,526.46
5. Step 5: Solve for x
   x = 354,644,526.46/21,120.30
6. Step 6: Final answer
   x = 16,791.64