Finding the Fourth Proportional to 20,912.55, 28,846.64 and 12,409.07

Step by Step Solution

1. Step 1: Write the proportion equation
   20,912.55 : 28,846.64 = 12,409.07 : x
2. Step 2: Convert to fraction form
   20,912.55/28,846.64 = 12,409.07/x
3. Step 3: Cross multiply
   20,912.55x = 28,846.64 × 12,409.07
4. Step 4: Simplify right side
   20,912.55x = 357,959,871.89
5. Step 5: Solve for x
   x = 357,959,871.89/20,912.55
6. Step 6: Final answer
   x = 17,116.99