Finding the Fourth Proportional to 21,406.76, 29,541.54 and 12,909.32

Step by Step Solution

1. Step 1: Write the proportion equation
   21,406.76 : 29,541.54 = 12,909.32 : x
2. Step 2: Convert to fraction form
   21,406.76/29,541.54 = 12,909.32/x
3. Step 3: Cross multiply
   21,406.76x = 29,541.54 × 12,909.32
4. Step 4: Simplify right side
   21,406.76x = 381,361,193.15
5. Step 5: Solve for x
   x = 381,361,193.15/21,406.76
6. Step 6: Final answer
   x = 17,814.99