Finding the Fourth Proportional to 15,789.52, 21,789.55 and 8,715.93

Step by Step Solution

1. Step 1: Write the proportion equation
   15,789.52 : 21,789.55 = 8,715.93 : x
2. Step 2: Convert to fraction form
   15,789.52/21,789.55 = 8,715.93/x
3. Step 3: Cross multiply
   15,789.52x = 21,789.55 × 8,715.93
4. Step 4: Simplify right side
   15,789.52x = 189,916,148.95
5. Step 5: Solve for x
   x = 189,916,148.95/15,789.52
6. Step 6: Final answer
   x = 12,027.99