Finding the Fourth Proportional to 15,789.97, 21,788.89 and 8,715.43

Step by Step Solution

1. Step 1: Write the proportion equation
   15,789.97 : 21,788.89 = 8,715.43 : x
2. Step 2: Convert to fraction form
   15,789.97/21,788.89 = 8,715.43/x
3. Step 3: Cross multiply
   15,789.97x = 21,788.89 × 8,715.43
4. Step 4: Simplify right side
   15,789.97x = 189,899,545.57
5. Step 5: Solve for x
   x = 189,899,545.57/15,789.97
6. Step 6: Final answer
   x = 12,026.59