Finding the Fourth Proportional to 12,789.86, 17,648.40 and 7,123.18

Step by Step Solution

1. Step 1: Write the proportion equation
   12,789.86 : 17,648.40 = 7,123.18 : x
2. Step 2: Convert to fraction form
   12,789.86/17,648.40 = 7,123.18/x
3. Step 3: Cross multiply
   12,789.86x = 17,648.40 × 7,123.18
4. Step 4: Simplify right side
   12,789.86x = 125,712,729.91
5. Step 5: Solve for x
   x = 125,712,729.91/12,789.86
6. Step 6: Final answer
   x = 9,829.09