Finding the Fourth Proportional to 12,789.50, 17,648.35 and 7,123.75

Step by Step Solution

1. Step 1: Write the proportion equation
   12,789.50 : 17,648.35 = 7,123.75 : x
2. Step 2: Convert to fraction form
   12,789.50/17,648.35 = 7,123.75/x
3. Step 3: Cross multiply
   12,789.50x = 17,648.35 × 7,123.75
4. Step 4: Simplify right side
   12,789.50x = 125,722,371.38
5. Step 5: Solve for x
   x = 125,722,371.38/12,789.50
6. Step 6: Final answer
   x = 9,830.13