Finding the Fourth Proportional to 22,789.88, 31,451.61 and 12,720.28

Step by Step Solution

1. Step 1: Write the proportion equation
   22,789.88 : 31,451.61 = 12,720.28 : x
2. Step 2: Convert to fraction form
   22,789.88/31,451.61 = 12,720.28/x
3. Step 3: Cross multiply
   22,789.88x = 31,451.61 × 12,720.28
4. Step 4: Simplify right side
   22,789.88x = 400,073,064.79
5. Step 5: Solve for x
   x = 400,073,064.79/22,789.88
6. Step 6: Final answer
   x = 17,554.86