Finding the Fourth Proportional to 12,643.29, 17,446.89 and 6,978.05

Step by Step Solution

1. Step 1: Write the proportion equation
   12,643.29 : 17,446.89 = 6,978.05 : x
2. Step 2: Convert to fraction form
   12,643.29/17,446.89 = 6,978.05/x
3. Step 3: Cross multiply
   12,643.29x = 17,446.89 × 6,978.05
4. Step 4: Simplify right side
   12,643.29x = 121,745,275.12
5. Step 5: Solve for x
   x = 121,745,275.12/12,643.29
6. Step 6: Final answer
   x = 9,629.24