Finding the Fourth Proportional to 21,364.56, 29,478.06 and 12,406.76

Step by Step Solution

1. Step 1: Write the proportion equation
   21,364.56 : 29,478.06 = 12,406.76 : x
2. Step 2: Convert to fraction form
   21,364.56/29,478.06 = 12,406.76/x
3. Step 3: Cross multiply
   21,364.56x = 29,478.06 × 12,406.76
4. Step 4: Simplify right side
   21,364.56x = 365,727,215.69
5. Step 5: Solve for x
   x = 365,727,215.69/21,364.56
6. Step 6: Final answer
   x = 17,118.41