Finding the Fourth Proportional to 12,939.75, 17,856.86 and 7,634.57

Step by Step Solution

1. Step 1: Write the proportion equation
   12,939.75 : 17,856.86 = 7,634.57 : x
2. Step 2: Convert to fraction form
   12,939.75/17,856.86 = 7,634.57/x
3. Step 3: Cross multiply
   12,939.75x = 17,856.86 × 7,634.57
4. Step 4: Simplify right side
   12,939.75x = 136,329,345.30
5. Step 5: Solve for x
   x = 136,329,345.30/12,939.75
6. Step 6: Final answer
   x = 10,535.70