Finding the Fourth Proportional to 21,109.86, 29,133.60 and 12,612

Step by Step Solution

1. Step 1: Write the proportion equation
   21,109.86 : 29,133.60 = 12,612 : x
2. Step 2: Convert to fraction form
   21,109.86/29,133.60 = 12,612/x
3. Step 3: Cross multiply
   21,109.86x = 29,133.60 × 12,612
4. Step 4: Simplify right side
   21,109.86x = 367,432,963.20
5. Step 5: Solve for x
   x = 367,432,963.20/21,109.86
6. Step 6: Final answer
   x = 17,405.75