Finding the Fourth Proportional to 23,121.12, 31,906.56 and 12,912.48

Step by Step Solution

1. Step 1: Write the proportion equation
   23,121.12 : 31,906.56 = 12,912.48 : x
2. Step 2: Convert to fraction form
   23,121.12/31,906.56 = 12,912.48/x
3. Step 3: Cross multiply
   23,121.12x = 31,906.56 × 12,912.48
4. Step 4: Simplify right side
   23,121.12x = 411,992,817.87
5. Step 5: Solve for x
   x = 411,992,817.87/23,121.12
6. Step 6: Final answer
   x = 17,818.90