Finding the Fourth Proportional to 20,912.17, 28,846.12 and 12,408.69

Step by Step Solution

1. Step 1: Write the proportion equation
   20,912.17 : 28,846.12 = 12,408.69 : x
2. Step 2: Convert to fraction form
   20,912.17/28,846.12 = 12,408.69/x
3. Step 3: Cross multiply
   20,912.17x = 28,846.12 × 12,408.69
4. Step 4: Simplify right side
   20,912.17x = 357,942,560.78
5. Step 5: Solve for x
   x = 357,942,560.78/20,912.17
6. Step 6: Final answer
   x = 17,116.47