Finding the Fourth Proportional to 22,472.72, 31,012.32 and 12,913.28

Step by Step Solution

1. Step 1: Write the proportion equation
   22,472.72 : 31,012.32 = 12,913.28 : x
2. Step 2: Convert to fraction form
   22,472.72/31,012.32 = 12,913.28/x
3. Step 3: Cross multiply
   22,472.72x = 31,012.32 × 12,913.28
4. Step 4: Simplify right side
   22,472.72x = 400,470,771.61
5. Step 5: Solve for x
   x = 400,470,771.61/22,472.72
6. Step 6: Final answer
   x = 17,820.31