Finding the Fourth Proportional to 12,947.83, 17,867.31 and 7,640.71

Step by Step Solution

1. Step 1: Write the proportion equation
   12,947.83 : 17,867.31 = 7,640.71 : x
2. Step 2: Convert to fraction form
   12,947.83/17,867.31 = 7,640.71/x
3. Step 3: Cross multiply
   12,947.83x = 17,867.31 × 7,640.71
4. Step 4: Simplify right side
   12,947.83x = 136,518,844.85
5. Step 5: Solve for x
   x = 136,518,844.85/12,947.83
6. Step 6: Final answer
   x = 10,543.77